Wireframe

A readme file in a repository is used to tell other people the followings: what your porject does, why the project is usefull, what they can do with you project, How the users can get started with it, and etc.

The wireframe acts as a blueprint or skeleton of a website or an application. It structures the layout and visual designs like what colors and fonts to be used. Simply it shows what elements should go where in a website or application.

A branch is a sequence of commits in a project. In other words, a branch is a separate workspace of the same project where you can make modifications and try new ideas without affecting the master or main branch of the project. Once everything looks okay and you and your team are okay with the design, you can then merge the changes from your branch to the main branch.