What is the meaning of synchronous?

adjective

• Occurring or existing at the same time or having the same period or phase.
  • usage: "recovery was synchronous with therapy- Jour. A. M. A.; "a synchronous set of clocks"; "the synchronous action of a bird's wings in flight"; "synchronous oscillations"
  • synonyms: synchronal, synchronic
• Digital communication) pertaining to a transmission technique that requires a common clock signal (a timing reference) between the communicating devices in order to coordinate their transmissions. (.