Difference Between HashMap and HashTable ?

Difference Between HashMap and HashTable ?

HASH MAP	HASH Table
Both provide key-value access to data	Both provide key-value access to data
HashMap not synchronized	Hashtable is synchronized
iterator in the HashMap is fail-safe Fail-safe is relevant from the context of iterators.If an iterator has been created on a collection object and some other thread tries to modify the collection object "structurally",a concurrent modification exception will be thrown	Synchronized means:- only one thread can modify a hash table at one point of time. Basically, it means that any thread before performing an update on a hash table will have to acquire a lock on the object while others will wait for lock to be released.
you can make Hashmap as synchronize : Map m = Collections.synchronizeMap(hashMap)
Since HashMap is not thread safe so it is faster than hashTable

HashMap:  if you are sure that this hashmap will not be accessed by multiple threads 

but if you want to multiple thread to access then use HashTable.