There are lots of resources about HashTable vs HashMap vs ConcurrentHashMap . The main point is around synchronization. Hashtable is synchronized, whereas HashMap is not. This makes
HashMapbetter for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones. On the other hand, if you need better performing synchronization, you should use ConcurrentHashMap. In this article, it is simply explained how ConcurrentHashMap performs better than HashTable.