An Off plan property is an Under construction Property which you pay in easy installments without any interest rate

Usually the Payment plans spans till the construction is completed e.g 4 Years.
But there are some developers which also offers a Post Handover Payment Plans, which means that you will keep paying the installments even after you receive the keys of your property. Like a mortgage without interest rates

DLD — Dubai Land Department. This is the standard 4% Land department fee which you will pay once you buy any property in Dubai.
In an Off Plan property in Dubai, DLD will look over your Installments and make sure your purchase is secure and Developer will deliver the project on time

Escrow Account is the safety measure to guarantee the interests of the people who are buying Off Plan Property in UAE.
When you buy an Off Plan property in UAE, The money goes into an Escrow account Provided by the developer. In that Escrow Account there are three Parties — Buyer, Developer and the DLD. So that means the DLD (Dubai Land Department) will over look that money until the developer delivers the keys to the owner in time. Until the property is under construction the Developer cannot access the money in that escrow account

A Freehold Property is the one you own completely and 100% rights belong to you.
Leasehold Property is the one which you hold for 50-100 years only, like a extended rental contract