thread

thread interference: you don’t want two threads to interleave while accessing shared variables .. inconsistencies arise
deadlock: don't want to be stuck in a situation where each of the thread is waiting for the other thread to release a lock .. none of the thread can make any progress ..
starvation: don't want a thread to starve for resources being consumed by the other thread .. long and 'greedy' synchronized methods lead to this ..
livelock: pretty much like deadlock but the threads are not blocked waiting for each other but they are continuously responding to each other requests ... but none of them is able to make any progress ...