How many speakers are there in iPhone 15 Pro Max?

Hello,

When I bought the iPhone 15 Pro Max, I had the impression that there were two speakers on the bottom of the phone, but today, as usual, when I accidentally covered the speaker with my finger, I felt sound vibrations only from one speaker on the right side, is the speaker on the left side a microphone in the iPhone 15 Pro Max?

Sorry for the stupid question, but it's bothering me.

Best Regards.

[Re-Titled by Moderator]