Definition - What does Synchronous mean?
Synchronous refers to events and processes that occur simultaneously or have dependencies relating to time or another event that relies on time.
Techopedia explains Synchronous
In telecommunications. synchronous refers to signals that are sent and received with specific timing. This means that both the sender and receiver use the same clock cycle and know exactly when the signal is sent and when it should be received, essentially working in fixed time intervals, so an error results only when signals are not sent or received at expected times.
In terms of data processing, synchronous refers to blocking communications (synchronous I/O) that occur on the same thread as other computations, thereby preventing continuation until these communications are completed.