The End in Minecraft refers to one of three dimensions. This includes the Nether and Overworld. Although it is the "end", Minecraft doesn't end. Although the game can be defeated, it will continue on indefinitely. The End is the most dangerous place in Minecraft.
There is an end portal, which is a gateway of sorts, in the End. It can transport players to another place.
End gateways are portals created after the Ender Dragon is killed. These portals are used to access the outer End Islands. These portals can only be reached if you find the End, enter it, and defeat the Dragon. This is very difficult.
After defeating the Ender Dragon, End Cities can be a cool place. While killing the mob is the primary goal of the End, there are many other things to do if you don't want to return to the Overworld immediately.
A nearby End gateway will open once the dragon has been defeated. Only one way is there to get through it: an Ender pearl.
Players must throw an Ender pearl in the portal section to gain access to an End gateway. You can't walk in because there will be Bedrock blocks surrounding and above it. To prevent the Ender pearl from being teleported to another place, or into the Void, make sure you throw it directly into the portal.
After they have entered the End gateway they will be taken to the End Islands. Many of these islands can have an End City, which offers great loot. Players will need to return their Ender pearls. It is recommended that they have at least one.