Entries is simply where you enter and store your section content. There are three types of entry content, singles, multiples and globals.
Multiples can have many entries, whereas singles can ONLY have one. Multiples can actually be accessed from anywhere, even in singles.
In the entry view, this is where you can let ignitedCMS Pro generate the folder and file structures in your views > custom folder. The engine will automagically collect all field types in that section and dump them into your template with the correct syntax.
Entries is where you actually enter your data