In the original Pokémon games, HMs are special "hidden" moves that you can use outside of battle to solve various puzzles. Here's how to get all of the HMs in Pokémon Red, Blue, and Yellow for all platforms.
Pokémon Red Blue & Yellow | All HM Locations
This is one of the easiest HMs to find. You need to have boarded the SS Anne, which requires an SS Ticket. You get this by helping Bill during his unfortunate teleportation accident that turns him into a Pokémon. You need to go to Vermilion City to board the SS Anne and battle your rival. Once you have fought and defeated your rival, you will be able to enter the Captain's Quarters.
You'll find an older man there who is seasick. If you give him a back rub, you'll be rewarded with HM01, which is Cut. You can use it in and out of battle, as a powerful attack or to cut through the bushes that get in your way here and there throughout the game.
It's an absolute necessity, just like the rest of the HMs, so make sure you get it in the game as soon as possible so you can explore additional areas.
