New Server 2 What Is The Different Bound And Unbound

What is the different a bound and unbound item and also how can i see if the item is bound?

 1.a item of bound is can't be trade or can't be donate in our guild vault also it may see to many item has a lock🔒. 

2.a unbound item is can be traded or can be donated in our guild vault also clear from the item or also known as no lock or unlock🔓.