When you accept a purchase offer for your home, escrow begins.
The escrow period is the time from offer acceptance to the day the title of your home officially changes from you to the new buyer.
During that time period the buyer of your property is doing their inspections and getting the loan to buy the home.
A buyer using a conventional loan (5% or more for the down payment) will usually close in 30 days.
However, a cash buyer doesn't have to go through the loan process, so they usually close in 7 - 14 days.
Buyers using a FHA loan usually close in 45 days.