Microphones output mic level signals. These mic level signals require amplification to become line level signals (for use in mixing boards, digital audio workstations, and audio recorders). Microphone preamplifiers provide this gain. Therefore, microphones typically plug into microphone preamplifiers!

Can a microphone work without an amplifier?

Passive loudspeakers: passive loudspeakers do not have amplifiers and therefore cannot apply any gain to the mic level signal. A mic level signal is far too weak to drive a speaker. Active microphones: active microphones require some sort of power in order to function (typically DC bias or phantom power).

Do microphones use amplifiers?

A microphone is a transducer that converts sound (mechanical wave energy) into audio (electrical energy). Mics do not amplify sound, per se, though some mics do amplify the audio signal from their capsules before the signal is outputted. All mics require further amplification beyond their own.