End Portal Frames are special blocks in the game Minecraft that are used to create an End Portal. These frames are arranged in a rectangular shape, typically in a 3x3 layout, with a space in the center for the portal itself. Each frame can hold an Eye of Ender, which is necessary to activate the portal. To find End Portal Frames, players must explore Strongholds, which are underground structures. Once all the frames are filled with Eyes of Ender, the portal activates, allowing players to enter the End, a dimension where they can encounter the Ender Dragon and other unique challenges.