* Cut: This HM allows you to cut down trees and bushes that block your path. You learn it from the man in the house on the left side of the entrance to Viridian Forest.
* Strength: This HM allows you to push boulders out of the way. You learn it from the man on the right side of the entrance to Viridian Forest.
* Flash: This TM allows you to see in dark areas. While it doesn't break obstacles, it allows you to explore areas you might not be able to see otherwise.
* Fly: This HM allows you to quickly travel between cities and towns that you've already visited. It can save you time if you need to get around obstacles.
Remember that you can only carry a limited number of HMs and TMs at once, so choose wisely!