{"id":1438,"date":"2020-12-08T17:09:01","date_gmt":"2020-12-08T17:09:01","guid":{"rendered":"https:\/\/sectigostore.com\/blog\/?p=1438"},"modified":"2020-12-10T11:36:02","modified_gmt":"2020-12-10T11:36:02","slug":"tcp-vs-udp-whats-the-difference","status":"publish","type":"post","link":"https:\/\/sectigostore.com\/blog\/tcp-vs-udp-whats-the-difference\/","title":{"rendered":"TCP vs UDP \u2014 What\u2019s the Difference Between Them?"},"content":{"rendered":"\n

TCP and UDP are both ways that you transmit data across networks \u2014 but as much as they\u2019re the same, they\u2019re also different. Here\u2019s what to know about these different internet protocols and how they work\u2026.<\/h2>\n\n\n\n

TCP vs UDP \u2014 what is the difference between TCP and UDP?<\/p>\n\n\n\n

When it comes to understanding TCP vs UDP<\/strong> \u2014 or what’s known as the transmission control protocol<\/strong> and the user datagram protocol<\/strong> \u2014 there\u2019s quite a bit to know. In the most basic sense, it comes down to understanding that they\u2019re variations of the same thing and that they operate in different ways.<\/p>\n\n\n\n

In a nutshell, they’re similar (yet different) internet protocols that transfer data. More specifically, TCP and UDP are both communication protocols.<\/strong> But there\u2019s more to them than just that. To help you better understand, we\u2019ll cover what TCP and UDP are individually \u2014 their similarities, their individual purposes, and how they work. After that, we\u2019ll highlight the difference between TCP and UDP in a handy table.<\/p>\n\n\n\n

But first, let\u2019s better get a handle on what an internet protocol is to set the foundation for the topic.<\/p>\n\n\n\n

Table of contents<\/p>

<\/polyline><\/svg><\/div>
  1. TCP and UDP are both ways that you transmit data across networks \u2014 but as much as they\u2019re the same, they\u2019re also different. Here\u2019s what to know about these different internet protocols and how they work\u2026.<\/a>
      <\/ol><\/li>
    1. What Is the Internet Protocol?<\/a>
      1. IP, TCP, and UDP Are All Protocols Within the Layers of the OSI Model<\/a>
          <\/ol><\/li>
        1. How the IP Works to Transfer Data<\/a>
            <\/ol><\/li>
          1. The Internet Protocol is the Delivery Service of the Internet<\/a>
              <\/ol><\/li><\/ol><\/li>
            1. TCP vs UDP: Everything You Need to Know About These Protocols<\/a>
              1. What Is TCP?<\/a>
                1. How TCP Works in Exchanging Data<\/a>
                    <\/ol><\/li><\/ol><\/li>
                  1. What Is UDP?<\/a>
                    1. How UDP Works in Exchanging Data<\/a>
                        <\/ol><\/li><\/ol><\/li>
                      1. A Summary of the Differences Between TCP and UDP<\/a>
                        1. TCP vs UDP: Differences in Terms of Data Delivery (an Example)<\/a>
                            <\/ol><\/li><\/ol><\/li>
                          1. TCP vs UDP Applications: When Is One Method Better Than the Other?<\/a>
                              <\/ol><\/li><\/ol><\/li>
                            1. TD;DR \u2014 The Key Differences Between TCP vs UDP<\/a>
                                <\/ol><\/li><\/ol><\/div>\n\n\n\n

                                What Is the Internet Protocol?<\/h2>\n\n\n\n

                                The internet protocol (IP), a type of network protocol, is a set of rules that dictate how data sends or transmits to an intended recipient via the local network, across subnets or even the Internet. So, for example, whenever you send data from your web browser to a website \u2014 like when you order dog treats in bulk from your favorite pet supply website \u2014 you do so via the internet protocol.<\/p>\n\n\n\n

                                In a roundabout way, internet protocol data transmissions allow you to do everything you do online \u2014 from tweeting on social media and researching recipes to sending emails with images or your favorite cat videos. Essentially, it\u2019s the foundation of the internet.<\/p>\n\n\n\n

                                IP, TCP, and UDP Are All Protocols Within the Layers of the OSI Model<\/h3>\n\n\n\n

                                I mentioned that IP is a network protocol. The network is just one of seven layers of the ISO\u2019s open systems interconnection (OSI) model<\/a>. The model serves as the vertical framework and standards that guide how information exchanges among computing systems. The seven layers of the OSI model are:<\/p>\n\n\n\n

                                1. Physical layer<\/li>
                                2. Data link layer<\/li>
                                3. Network layer<\/li>
                                4. Transport layer<\/li>
                                5. Session layer<\/li>
                                6. Presentation layer<\/li>
                                7. Application layer<\/li><\/ol>\n\n\n\n

                                  Typically, this is visualized vertically in descending order with the physical layer being the lowest layer. As such, it traditionally looks something like this:<\/p>\n\n\n\n

                                  \"A
                                  An illustration that outlines the 7 layers of the ISO’s open systems interconnection model.<\/figcaption><\/figure><\/div>\n\n\n\n

                                  TCP and UDP, on the other hand, are two of the protocols that fall within the transport layer of the OSI model. Now, there are actually a variety of protocols out there that fall within the seven layers and serve different functions \u2014 and many are built upon one another. We\u2019re not going to get into all of those today since the purpose of this article is to help you understand TCP vs UDP.<\/p>\n\n\n\n

                                  Before we can get into the nitty-gritty of discussing the difference between TCP and UDP, you first need to understand how the internet protocol works. I say this because TCP and UDP both rely on IP. This will serve as a foundation for helping to explain the other two concepts.<\/p>\n\n\n\n

                                  How the IP Works to Transfer Data<\/h3>\n\n\n\n

                                  Regardless of what you\u2019re sending, the data travels back and forth across the internet through a process known as routing<\/strong>. As you can probably guess, this process involves the use of routers or gateways to regulate traffic. According to a TechRepublic article<\/a> by network engineer and tech writer Brien Posey, routers are typically for similar networks, whereas gateways help to bridge dissimilar networks.  <\/p>\n\n\n\n

                                  Now, to ensure that the data reaches the intended recipient, every individual device has its own assigned IP address<\/strong> \u2014 much like you have a specific address for your house or apartment. But instead of 123 Main Street, your IP address on the internet might look something like 250.250.250.250 (if you\u2019re using a standard IPv4 address). This 32-bit number consists of a series of subnets<\/a> (segments of numbers that are divided by periods) \u2014 each of which contains up to three digits (for up to a total of 12 digits or 15 characters, including the periods).<\/p>\n\n\n\n

                                  Of course, this looks different for IPv6 IP addresses, which are 128-bit numbers and look akin to this: 2001:0db8:85a3:0000:0000:8a2e:0370:7334 (this is an example IPv6 address from Wikipedia<\/a>).  <\/p>\n\n\n\n

                                  Before transferring your data, the IP breaks it down into smaller PDUs \u2014 these are known as packets<\/strong> (for TCP) or datagrams<\/strong> (for UDP). Packets is the most commonly used term for data units in networking. This breakdown of data happens with all IP data transfers \u2014 TCP and UDP alike. Each of these individual little bundles of data is slapped with a label (header<\/strong>) that tells the delivery person where it needs to go and where it was sent from.<\/p>\n\n\n\n

                                  The data is transferred routers<\/strong> or gateways<\/strong> that have lists information for different IP addresses (and their corresponding domains) across the internet. The info transfers from one gateway to the next until one of them recognizes the package or datagram\u2019s destination.<\/p>\n\n\n\n

                                  Now, just keep in mind that this is a (highly) simplified breakdown of how IP works. Just keep this illustration in mind because I’m going to come back to it later and apply TCP and UDP as the delivery methods. <\/p>\n\n\n\n

                                  If you\u2019re wondering where the domain name system (DNS) fits into all this (since it\u2019s essentially what connects domains with their corresponding IP addresses), just know that it\u2019s related but separate. For example, the domain name system can use UDP for DNS requests. However, we\u2019re not going to get into all of that here because that\u2019s just a whole separate process and the focus of this article is honing in on the differences between TCP vs UDP. So, we\u2019ll have to cover the DNS system more in depth in a future article.<\/p>\n\n\n\n

                                  The Internet Protocol is the Delivery Service of the Internet<\/h3>\n\n\n\n

                                  Okay, let\u2019s put all of this into a little context. Think of the internet protocol like the FedEx, DHS, or USPS of the internet \u2014 but with a bit of a twist (I\u2019ll explain more shortly). With these types of mail delivery services, you can choose to send packages via basic delivery, or you can choose to have someone sign for the packages upon arrival to ensure they\u2019ve reached the right person. The internet protocol works much the same way but for digital data transmissions.<\/p>\n\n\n\n

                                  Now, continuing with the delivery service analogy, imagine that your mom wants to send you a BUNCH of home baked items: cookies, breads, dehydrated fruits \u2014 you name it. (You lucky devil.) To do this, she\u2019d need to have your address to ensure the oversized package get delivered to your doorstep successfully. Otherwise, those delicious treats could end up in the hands of your least favorite neighbors, Greg and Jill (and nobody wants that).<\/p>\n\n\n\n

                                  So, in this case, your mom would package everything up, label the package with your address (header<\/strong>), and request for her favorite delivery company to come get \u2018em. (Again, I\u2019m really<\/em> simplifying things here \u2014 cut me some slack.) However, she winds up having to break down the box into a series of smaller labeled boxes (packets<\/strong> or datagrams<\/strong>) because it\u2019s just too much to handle.<\/p>\n\n\n\n

                                  Once the packages leave her house, they wind up at the transfer station (gateway<\/strong>) to make their way to the next delivery point closest to the destination. There, the packages make their way from station to station (gateway to gateway<\/strong>) until they get to the one that knows your exact address.<\/p>\n\n\n\n

                                  Now, imagine that delicious package is instead data that\u2019s transmitting across the internet. Now, what happens to those packages at this point will vary depending on whether the delivery occurs via TCP or UDP. I\u2019ll explain what I mean by that momentarily \u2014 but first, let\u2019s get a primer on what TCP and UDP are and what each data transmission method entails.<\/p>\n\n\n\n

                                  TCP vs UDP: Everything You Need to Know About These Protocols<\/h2>\n\n\n\n

                                  What Is TCP?<\/h3>\n\n\n\n

                                  TCP stands for transmission control protocol<\/strong>, which is a type of connection-oriented data communication method<\/strong>. It was designed to help establish reliable connections on virtually any network \u2014 even those that are unreliable. TCP, which is dependent upon IP, is part of the transport layer of the ISO\u2019s open system interconnection (OSI) model<\/a>. This means it\u2019s a transport layer communication protocol.<\/p>\n\n\n\n

                                  But how do you know if you\u2019re using TCP? You know that buffering symbol that pops up sometimes when you\u2019re trying to load a high-quality video on your favorite video website? That\u2019s frequently a sign that the data you\u2019re receiving is being transmitted via TCP.<\/p>\n\n\n\n

                                  Basically, the goal of TCP is to be an error-free method of data transmission. The transmission control protocol helps to:<\/p>\n\n\n\n

                                  1. Ensure the recipient receives all<\/em> of the data that\u2019s sent (via a delivery receipt), and<\/li>
                                  2. Keep the data transmissions organized by ensuring that packets are received by the recipient in their intended order.<\/li><\/ol>\n\n\n\n

                                    TCP does this by establishing a reliable connection that helps it to verify that packets are received successfully. Basically, if the data arrives as intended, in the order it\u2019s supposed to, then it receives a confirmation from the recipient. If not, then the TCP will have the sender re-send the data again.   <\/p>\n\n\n\n

                                    The TCP protocol was first defined in 1980 by the Internet Engineering Task Force (IETF) in its RFC 761<\/a>. It was later obsoleted by RFC 793<\/a> in 1981. Historically, it\u2019s been a very common method of data transmission \u2014 one that you likely use on a daily basis as you go about your day on the internet.<\/p>\n\n\n\n

                                    However, it\u2019s not perfect and may not be the most suitable protocol to use in all cases. This is where UDP (or other communication protocols) comes into play. (More on UDP momentarily.)<\/p>\n\n\n\n

                                    How TCP Works in Exchanging Data<\/h4>\n\n\n\n

                                    The transmission control protocol requires establishing a connection via a three-way handshake<\/strong> before transferring data packets from the server to the client. The three-way handshake process<\/a>, which starts with the exchange of SYN, SYN-ACK, and ACK messages (known as flags) between these entities, helps to ensure that a reliable connection is made between them. It looks something like this:<\/p>\n\n\n\n

                                    \"TCP
                                    An illustration of the three-way handshake<\/figcaption><\/figure><\/div>\n\n\n\n

                                    The three messages are the following:<\/p>\n\n\n\n