Version Control and Significance of Git

Version control

Suppose we’re assigned to work on a project. When we decide to add a new feature, we realize that something we did earlier won’t allow our new feature to work correctly. We then try to revert those changes. However, we encounter a problem regarding whether or not we made similar changes in the other files.

Luckily, there’s a way for us to identify the exact changes we made and where in our code we made them. This technique to track changes in the source code is known as version control.

Version control is useful because of the following:

• It keeps track of the changes made to the codebase. Version control systems allow us to track how our project changes over time. They also provide additional information about why and when each change was incorporated.

• It facilitates collaboration. Version control systems track how our source code changes, who changes it, and when it changes. It also allows us to revert those changes as we deem fit.

• Version control tools are continuously updated. They follow the ever-changing workflows that developers choose to use. Git is now seen as the tool of choice for version control.

Git

Git is a distributed version control software. With Git, a complete copy of the entire codebase is available on every contributor’s computer. We can call this copy of the codebase a local repository. Git tracks the local repository and maintains a record of all the changes that occur within it. It removes the hassle of users needing to keep multiple versions of the project in separate directories and allows for seamless and quick exchange of changes between collaborators.

The distributed nature of Git makes it unique and efficient. Since every contributor or collaborator has their own clone of the source code in their local repository, Git can quickly track, add, or revert changes. Git uses the local database to keep a record of the changes made to the project files. The four phases of Git are shown in the figure below. We’ll learn about these phases of Git in the upcoming lessons.

How does Git differ from other version control systems?

The key differences between Git and other version control systems are given below:

• With the right permission, we can change the history in our copy of the repository and that of others.

• Other version control systems take $O(n)$, where $n$ is the number of files, in order to branch a repository. Git, however, takes $O(1)$. This means that the same amount of time is always required to branch a repository, regardless of the size of the repository.

• Changes are made at the project level and not per file. Thus, there’s no issue of a loss of history when a file is moved or renamed. This is a massive win for Git over CVS, which is a file-oriented version control system.

• Git doesn’t automatically number the versions of files or changes. Instead, it assigns a random hash or commit ID to the change made to the repository (commits), which refers to those changes and has applications like cherry-pick.