Let's say you have your application template and a team of five people working on it. One Monday morning you decide to change a minor thing, such as the security group, and at the same time your colleague, sitting in a room next to you, decides to change a disk size for instances. Being confident that you are the only ones running the terraform apply command at this moment, you both do terraform apply, push changed state file to the git repository (or to remote storage like S3), and end up in a total disaster.
If your state file is stored in git, then you will meet the merge conflict: not too bad, you can try to resolve it by hand, and you will still be able to see who changed what. If you use a remote ...
