What will happen if there are multiple field section with same name?
Its a general question, and I thought if there are multiple Field Sections, the Content Editor will get confused while changing the content.
Template field sections are for grouping purposes only. It doesn't matter if there are multiple sections with the same name. If there are multiple sections with the same name, Sitecore will display all their fields under one section while author wants to edit item based on that template in Content Editor.
It's different with fields. It is possible to use fields with same name but it's not recommended. That would only allow you to access fields by field ID, not field name and can be really confusing for content editors.