Overview
A lead/Quote status is setup with a function, the function prompts an action within the system.
You can have as many statues as required. With the ability to update to different colours (this is displayed in your calendar).
If you have multiples statuses with the same function the status that is first in sequence is the status that will prompt that function when required.
Emails can be setup to send on status change see here for setup → Email Templates
To access these menu's select 
Settings - Sales Settings, then at the top select the relevant tab or you can access the CSV by selecting Import Export Sales Settings
Lead Status
Lead Status - Function Description
Order Status
Order Status - Function Description
Example