PWM audio amplifier and DAC audio amplifier

HI,
1. what's the difference between PWM audio amplifier and DAC audio amplifier ?
2. Normally, Common PC Amp belongs to PWM or DAC ?
3. How to convert from PWM into DAC ?

PWM is a type of DAC, and assuming you're talking audio power amplifiers is probably the only type used?.

To elaborate, PWM is a type of digital modulation that can be simply converted to analog by running through a low-pass filter (such as a speaker) thus giving a digital-to-analog conversion (DAC). DAC is a generic term and can apply to any type of digital-to-analog conversion. MP3 is a type of digital encoding, for example, that is converted to analog by a decoder/ DAC specifically designed for that purpose.