--- title: Parts of a URL slug: parts-of-a-url published_at: 2020-02-19 22:16:58 +0000 updated_at: 2026-03-04 20:14:59 +0000 summary: description: tags: [Web Development, URL, query string, path, domain, Fragment, Parts of a url, Scheme] views: 1492 author: CJ Avilla url: https://www.cjav.dev/videos/parts-of-a-url youtube_url: https://www.youtube.com/watch?v=GwVg5bvIl_g youtube_id: GwVg5bvIl_g embed_url: https://www.youtube.com/embed/GwVg5bvIl_g thumbnail_url: https://i.ytimg.com/vi/GwVg5bvIl_g/hqdefault.jpg type: video --- # Parts of a URL *Published: February 19, 2020* *Views: 1492* ## Watch [Watch on YouTube](https://www.youtube.com/watch?v=GwVg5bvIl_g) [![Parts of a URL](https://i.ytimg.com/vi/GwVg5bvIl_g/hqdefault.jpg)](https://www.youtube.com/watch?v=GwVg5bvIl_g) ## Description ## Transcript hey there just want to tell you a little bit about URLs it's a really simple concept but I just want to get some terminology under our belt so in the URL when you when you when you enter a URL into a browser bar this is the most common place that we're seeing URLs has a few components and those components will define what happens when a request is sent to the server so here we have a URL that's on Wikipedia for the page about URLs and you'll see that there is a scheme so the first part of the URL is the scheme so that's HTTP the second part is this colon followed by slash slash and then you can optionally have a user info meaning you can have like your login and password for basic authentication followed by an @ sign so these this part of the URL is optional so you might just have the slash slash and then the host that's like the most common thing that we'll see and these schemes you might see HTTPS you might also see FTP or mail there's a whole bunch of different things that you might see under the scheme I think there might be a list here so that's the scheme and then we have the host so the host is going to be what we also refer to as the domain there's kind of some interesting history here that Tim berners-lee wish that he instead of having dots in the domain had used slashes so it would have been like org slash Wikipedia /en slash wiki kind of interesting to think about so the domain is made up of a couple different parts too so we have this end org com do these are like common top-level domains or TLDs and then we also have the part that comes before Wikipedia org so this this might be considered the apex so Wikipedia org might be considered like the apex domain and then the the the pieces of the domain that come before that that last host end top-level domain are called the sub domain okay then we have a slash the slash is optional but implied so if you don't have a slash there and you're just going directly to like HTTP colon slash slash en dot wikipedia.org then without the slash and the slash is sort of implied and meaning that we're gonna go to the root we want to request the the root resource that lives at that slash then we we generally will have a path so in this case the path is slash wiki / URL and then in addition to the path you might also have a query string or a port so right here wikipedia.org the default port is 80 but if you had a specific port so I'm sorry for HTTP the default port is 80 and then for HTTP the port is 443 so these are going to be sort of inferred for you by the browser but the port specifies which port at the server you want to the the server program is bound to so you might need to specify the port sometimes when accessing a URL and a lot of times when you're working with a local server you'll put like localhost colon 3,000 that's because your local server is bound to port 3000 and that's like the program is that you are writing locally is tied to port 3000 this when you're working locally this is generally like a high port number because the lower port numbers are reserved and mostly for like public public access and you typically have to like set up your firewall to allow access through your network to those ports all right so then we have the path and after the path we might have a query string that starts with a question mark so here on DuckDuckGo I have we have this question mark here that is followed by a query string the query string is a like an ampersand separated set of attribute value pairs what instant they're not really like key value pairs they're attribute value pairs meaning that you can put in sort of like these braces here saying that we that queue is a list of URLs or you can say like queue x equals URL that means that like q is the top-level name that is pointing at a dictionary and in that dictionary there's a key X and the value for key X is URL so these are attribute value pairs that follow the query string so you'll have you have the scheme the domain or host the path then the query string and then after the query string so let's just put in something here for fun the you'll have this octothorpe or like the pound sign and the the part of the URL that comes after the pound sign is known as the fragment everything before the pound sign is passed to the server and it kind of acts as arguments into the server so you can kind of think of this as like wiki URL is a function that we're calling and we're passing in the the argument named Q with the value fun so that's that's kind of the way that I like to think about the the mental model around the URL that happens before the fragment and then generally the part after the fragment is used to to access a part of the page recent like in some modern web frameworks you might use this to like navigate around to different parts of the page but it also is used often to like jump to a specific part of the page so here if we click on this one right this one if you look down at the bottom of the URL bar you'll see that it is pointing to the fragment that is like the Citation note with a footnote ID so if we click on that we're gonna actually be on the same page the page did not make a full page refresh but we just navigated to a different part of the page and so that's this this link here is anchoring with that ID and so we're jumping down to this specific link on the page that's how you might use like table of contents or some really basic old-school page navigation you'll see this in like Google Docs a lot where you'll have a table of contents and then you when you're deep linking or like drilling down to a specific header you'll be navigating through the document with these the stuff that's in the fragment now also recently the html5 push API allows us to modify the URL just on the client and I'll continue to use the forward and back arrow to build like nice fancy single page applications where you don't really see a fragment so the fragment is kind of like an older way of navigating around but now that we have these really rich front-end applications from like angular ember react whatever you might end up using the html5 like push API to update that URL so that when you send a link like the point is that when you send someone a link you copy and paste this link and you send it to them or the URL you send it to them they should be able to jump to the specific resource on the page pretty quickly so hopefully that was helpful this would be I hope this is a good good reference material remember that everyone starts somewhere so Cheers --- [Back to all videos](https://www.cjav.dev/videos) --- ## Hey Agent, thanks for visiting! 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