data structures - Difference between "Complete binary tree", "strict binary tree","full binary Tree"?

Question

I am confused about the terminology of the below trees, I have been studying the Tree, and I am unable to distinguish between these trees:

a) Complete Binary Tree

b) Strict Binary Tree

c) Full Binary Tree

Please help me to differentiate among these trees. When and where these trees are used in Data Structure?

Answer 1

Perfect Tree:

       x
     /   
    /     
   x       x
  /      / 
 x   x   x   x
/  /  /  / 
x x x x x x x x

Complete Tree:

       x
     /   
    /     
   x       x
  /      / 
 x   x   x   x
/  /
x x x

Strict/Full Tree:

       x
     /   
    /     
   x       x
  /  
 x   x 
    / 
    x x