Version control in programming is handled through Git locally on your computer and through using the internet service of Github. Version control is helpful as it allows a new user to see the previous work, read what changed and/or why, and find out who contributed to it. A user can even go back in time and access the previous version. While saving versions on a computer by adding a number or date to the name of the file will work, it won't be pretty or easy to research the history of the code. Think of 300 versions of a website sitting on the desktop of a computer, a cringe worthy mess to work through. With the ease of Git and Github, this is avoided and a storyline of the code is streamlined.
Git saves the code with version control on a user's computer. Each time code is committed, it saves a separate version with a message, timestamp and records who committed it. Think of a super-duper type of saving. When code is committed, Git reviews the code to find the differences made and the user user can add a message to explain the commit. The user adds a short or long message to label the commit which future users (even the person who made the commit!) can use to figure out how the code changed. Not adding a message is frowned upon, don't be that person.
Github is where the code can be accessed online and where others can see, review, access, and improve it. By using Github, the user can always access their code (even then they are away from their laptop!) and so can others. The others part is where the real benefit comes in for using Github. The code being public means it can be improved by others, have features added on to it, and even used. Open Source is a term used for code put into the public for everyone to chip in, fix issues, build out, and utilize. This crowdsources the development of the code and frees up access to use it.
Version control will make your coding life easier by using Git and Github will make working and sharing of code social and more open.