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Version control is a system that records changes to a file or set of files over time so that you can recall specific versions later.
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#1. Git
Git is a free and open source distributed version control system designed to handle everything from small to very large projects with speed and efficiency.
Git allows and encourages you to have multiple local branches that can be entirely independent of each other.
Notably, when you push to a remote repository, you do not have to push all of your branches. You can choose to share just one of your branches, a few of them, or all of them. This tends to free people to try new ideas without worrying about having to plan how and when they are going to merge it in or share it with others.
There are ways to accomplish some of this with other systems, but the work involved is much more difficult and error-prone. Git makes this process incredibly easy and it changes the way most developers work when they learn it.
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#2. Github
GitHub is how people build software. With a community of more than 12 million people, developers can discover, use, and contribute to over millions projects using a powerful collaborative development workflow. In my opinion, it‘s just a website which provice some service for customer to place their code and help them to control their code‘s version. By the way, GitHub will ask the customer pay for their service if they need to set their projects into private status.
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#3. Gitlab
itLab is an open source tool used by developers to create and manage code bases collaboratively. Built on Git, which is a very popular and efficient distributed version control system, GitLab gives you all the tools needed for Git repository management from code reviews to issue tracking and more.
I think it‘s a copyer of the Github. but it‘s free and open source for our developer. I think it‘s very useful for us. We need to do somothing for the open source activity.