What does an amplifier actually do?

What is an amplifier, why do you need one? And what do they even do? What is a DAC?:    • What is a DAC and why do you need one?   Read more headphone, IEM, amp, and DAC Reviews: https://Headphones.com/TheAudioFiles Glossary of Audio Design and Measurement Terms: https://headphones.com/blogs/features... Our Editorial Policy: https://Headphones.com/TheAudioFiles/... Join our Discord server: https://go.headphones.com/discord How to read the new measurements:    • A new standard for headphone measurements   The 10 stages of headphone measurements    • The 10 stages you’ll go through when learn...   0:00 - Intro 0:55 - Gain 2:45 - Current/Power 4:48 - Output Impedance 7:07 - Outro