Thread (of execution) - a thread is simply the trace of a CPU’s PC over time not including context switch code execution by an RTOS. State information may or may not be associated with a thread of execution, but the value of the PC before a context switch is the minimum state that must be maintained on a system which includes preemption.
Throughput - an aggregate measure of speed and efficiency for a device - e.g. for a processor the measure is MIPS (Millions of Instructions Per Second) and for an I/O device the measure would be Mbps or Gbps (Mega bits/sec or Giga bits/sec).
Tick - a counter which counts interval timer interrupts and is used by an RTOS for basic timer services - e.g. to provide the minimum resolution for timeouts on blocking calls (the RTOS will unblock a call made with a timeout specified within tick accuracy).
Timeout - when making a blocking call, in order to avoid “wedging”, where a thread is blocked indefinitely, it is most often advisable to specify a timeout for any blocking call at which time the thread will be asynchronously awoken and will continue exeuction - this can be done by setting a timer that is set up to throw a signal to a timeout handler prior to making a blocking call if the API does not directly support a timeout option.