Synchronization is the process of allowing only one thread 
at atime on a shared resource. It is like a monitor on a 
shared resource.It can be done either 'Block level' 
or 'Method level'. Before enter in to the synchronized area 
the thread shold get the lock on the method or block object.

Two or more threads trying to access the same method at same
point of time leads to Synchronization.If that method is
declared as synchronized,only one thread can access at that
time of another thread can access that method only if the
first thread task is completed.

synchronization is a process in which only one thread 
executes at a time.when one thread release the resources 
then other thread used the resources.if one thread not 
release the resources till that time other thread not uses 
the resources.