Talking with a colleague face to face or on the phone are examples of synchronous communication.
Communication is a strategic process which involves the transfer of information (messages) from one person (sender) to another (recipient or receiver), especially through the use of semiotics, symbols, signs and network channel.
Generally speaking, talking with a colleague face to face or over the phone are examples of synchronous communication because they happen in real-time.
This ultimately implies that, synchronous communication makes it possible for the parties involved to receive a response in real-time or immediately.