T7L1 High Res

computers are becoming so embedded into our daily lives it's almost impossible to imagine a world without them but computers would be nothing without the code that tells them what to do in this lesson you'll learn what code is and how coders use it to help the world run smoothly you'll also learn about the world wide web and to coding languages that make it possible what is code code is sets of rules and instructions written in a specific programming language that helps us talk to machines just as humans speak different languages so do machines there are

hundreds of programming languages each suited to different tasks coders are people who understand and work with these languages on a daily basis so what does a coder do coders are the architects and builders of the digital world they use code to create programs that run on most of the machines you see and use every day from laptops to phones TVs cars and Internet connected fridges in fact the device you're using right now to listen to this lesson has a complex program that makes sure the screen the speakers microchip and you work together in harmony to

build these programs coders write small sequences of tasks that they want the machine to perform we call these sequences algorithms for example cars have computer programs that monitor all of their systems an algorithm within a cars program could be the following if a button is pressed on the car's dashboard make the engine status appear on the screen the amount of code can range from just a thousand lines which a simple mobile phone game would need to run to over two billion lines like the code that powers Google search engine let's focus on one of the

world's changing applications of code the world wide web did you know the Internet and the web are actually different things in fact the world wide web is just an application that's been built using the Internet let's break this down further the Internet is a global network of connections between computers that allows them to transfer information between each other we use the internet to send emails make calls watch videos and access the web through browsers like Chrome Firefox and Internet Explorer the web on the other hand is a collection of billions of pages of information that

have been made using code the most well known programming languages on the web include HTML hypertext markup language and CSS cascading style sheets imagine the internet as a city with roads and cables connecting everything and everyone together inside the city the buildings represent the web some of these buildings are libraries that store information some are cinemas where we go to watch films but all of them are made out of bricks or coding languages so how do coders use these languages well when you click on a link or type a web address you're actually asking another

computer to send you an HTML file that file contains the information your browser needs to display a web page although you immediately see this page of content as visually complete your browser actually receives hundreds of lines of HTML code telling its exactly which text images videos and spaces to display and where CSS is an additional coding language that shapes the visual style of a web page HTML defines what is displayed then CSS defines how it's displayed it makes sure that colors fonts and other style choices are applied to a webpage before you see it this

is useful when working with lots of HTML pages instead of coding the visual style into every single page you can just make one master CSS file and link each page to that now that we've explored the basics of coding from computer programs to algorithms HTML and CSS it's time to continue your learning try your hand at writing a bit of code yourself it's not as difficult as you might think check out the resources at the end of this video or explore one of the many coding tutorials available on the web