Which HashMap and TreeMap difference

1 round Medium: Theory + coding. [stream concept , Maven based qns like maven lifecycle, scope of spring, design pattern, Touch all collection concept like [Hashmap, ConcurrentMap, LinkedHashmap, Vector, List]], Stream coding part [count occerance of word]. 2 nd Round [More depth of java and springboot and also javascript as I mention in resume], Memory Management, exception Handling, try with multiple catch block, Transaction, Isolation, propagation. Coding I am not remember because I am not even understood the qns well and due to that I was blank in interview and mostly that I rejected.