What is the meaning of monitoring?

noun

• The act of observing something (and sometimes keeping a record of it. )
  • usage: "the monitoring of enemy communications plays an important role in war times"

verb

• Keep tabs on; keep an eye on; keep under surveillance.
  • usage: "we are monitoring the air quality"; "the police monitor the suspect's moves"
  • synonyms: monitor, supervise
• Check, track, or observe by means of a receiver.
  • synonyms: monitor