difference between deed of assignment & sale deed

assignment is ''a duty given to someone'' but the sale deed is ''transfer our right''. 

Deed of assignment :

Agreement under which some or all assets of an insolvent debtor are assigned to a trustee, for selling them and distributing the sale proceeds equitably among the creditors.

Sale agreement :

A sale deed acts as the main legal document for evidencing sale and transfer of ownership of property in favour of the buyer, from the seller.

Further, it also acts as the main document for further sale by the buyer as it establishes his proof of ownership of the property

"conveyance" or sale means
transfer of complete ownership whereas "assignment" means the transfer of the claim, right or
property to another and which may be conditional.