semaphore (4 facts) - A mechanism that allow data items to be locked so that they cannot be accessed by other threads when they are not ready
socket (1 kind, 4 facts) - Data in a client or server that represents an end of a TCP/IP connection. A complete connection has two sockets, one in the client and one in the server
synchronization (5 facts) - A mechanism to guarantee that only one thread can access an object at a time