NOTE This file was generated by Descript 1 00:00:01,230 --> 00:00:04,230 What do the terms front-end and backend mean? 2 00:00:04,470 --> 00:00:08,370 You'll encounter them early on when you learn about web development and 3 00:00:08,370 --> 00:00:09,840 they can be a little bit confusing. 4 00:00:10,649 --> 00:00:15,030 Front-end development concerns everything that the user interacts with directly. 5 00:00:15,329 --> 00:00:18,540 In web development, this means the things the user sees and 6 00:00:18,540 --> 00:00:20,490 does within the browser window. 7 00:00:20,850 --> 00:00:24,630 It's the content on the page, the images, the buttons, the text, et cetera. 8 00:00:25,350 --> 00:00:28,650 The code we write to produce this interface and behavior is sometimes 9 00:00:28,650 --> 00:00:32,940 called client-side code because it executes in the user's browser. 10 00:00:33,900 --> 00:00:36,959 The languages we used to write this code in modern web development are 11 00:00:37,050 --> 00:00:42,540 HTML 5, CSS 3 and JavaScript, each of which fills a specific role. 12 00:00:42,720 --> 00:00:45,870 And we'll talk about these technologies in detail in the next lecture and 13 00:00:45,870 --> 00:00:47,519 throughout the next couple of sections. 14 00:00:48,030 --> 00:00:52,260 Something important to note about these languages is the issue of compatibility. 15 00:00:52,620 --> 00:00:55,980 Because our HTML, CSS and JavaScript executes in the user's 16 00:00:55,980 --> 00:00:59,790 browser, it's up to the user's browser to run the code correctly. 17 00:01:00,570 --> 00:01:04,470 There's a single description of how features in HTML, CSS and 18 00:01:04,470 --> 00:01:07,980 JavaScript should work but different browsers sometimes interpret 19 00:01:07,980 --> 00:01:09,510 the specification differently. 20 00:01:09,750 --> 00:01:12,180 So you might get a new browser that behaves slightly 21 00:01:12,180 --> 00:01:14,340 differently given the same input. 22 00:01:14,730 --> 00:01:19,260 Also, older browsers may lack support for newer features of the three languages. 23 00:01:20,804 --> 00:01:25,035 Browser compatibility is a big part of writing front end code, so make sure 24 00:01:25,035 --> 00:01:28,785 that you're testing things in several browsers as you work through the course. 25 00:01:29,505 --> 00:01:31,604 The backend is the other side of the coin. 26 00:01:31,905 --> 00:01:35,835 When we do things in the browser which trigger requests to a server, such as when 27 00:01:35,835 --> 00:01:41,054 we submit a form, the backend code is what handles and responds to these requests. 28 00:01:41,804 --> 00:01:45,405 Backend or server-side code is predominantly concerned with storing 29 00:01:45,405 --> 00:01:49,095 information and controlling the flow of data through an application. 30 00:01:49,455 --> 00:01:52,935 This might mean restricting access to certain pages, storing and retrieving 31 00:01:52,935 --> 00:01:56,565 user information or dynamically populating pages with content. 32 00:01:57,420 --> 00:02:00,690 Many languages can be used for writing backend code like Ruby, 33 00:02:00,690 --> 00:02:03,150 JavaScript, Go, PHP, or Python. 34 00:02:03,390 --> 00:02:07,470 In this course, we'll use Python, together with a framework called Flask. 35 00:02:07,710 --> 00:02:10,919 Together these two make writing backend code much easier. 36 00:02:12,030 --> 00:02:14,910 Thank you guys for watching this video and I'll see you in the next one.