The actions menu contains all of the functions that allow you to add or create new items. Basically, you can think of this menu like this: it contains anything that you want to do that is a "Verb", excluding the items that are on the Modules Menu such as Create Purchase Orders. The actions menu is on every top-level record type and some of the menu items are in common with all top-level record types such as add a note, add a follow-up, attach a document, and add a phone message.
This should be the first place you look when you want to perform an action on a company.
