History: What is the the attack and release of a compressor do?

What is the the attack and release of a compressor do?

• These parameters impact how quickly the compressor will respond to changes in amplitude.
  Yes!
• We will reduce any amplitude over the attack and under the release.
  That doesn't make sense.
• Attack and release are a collection of individual compressors for specific frequency ranges.
  That is a multipressor.
• Attack and release determine how much we will reduce the amplitudes over the threshold.
  No, that's ratio.