This is a very broad question, much like saying "what is a human".
Depending on the map, who created it and what it was intended for, there can be infinite answers to this, but looking at it as a strategy game (Warcraft 3 Default Maps and Units), you may train units at the various buildings in Warcraft 3.
Sources:
I play Warcraft 3 a LOT. :)
What you are attempting to say does not make any sense and it sounds like you are asking "Is warcraft Pokemon world 3 a ho-ho?" make it clearer
"Warcraft 3 World Editor".
Go to "Object Editor". In there, you'll see a list of units and stuff. Look up and there will be a toolbar. It should list stuff like Units - Doodads - Destructibles - Abilities - Effects - ETC.... Click on the Abilties and you'll see the whole list of abilities in the whole game/map. You can change the abilities to add more damage and stuff or make your own custom ability.
Warcraft 3 World Editor, it should be located at your local Warcraft III file.
magic . . .
Warcraft 3 maps are by default melee maps unless you add more Triggers or player specific units, custom units...etc on the map...on the bottom right corner of the World Editor it tells you if it's either a melee map or a custom map (scenario) and the reasons why. Same goes for Frozen Throne.
Start>Programs>Warcraft 3 if it's not listed there re-download warcraft 3
There is no world of warcraft 3. There is world of warcraft, and warcraft 3. Unless you want to refer to Cataclysm. If so then no, you'd fail.
No, as Cataclysm is meant for World of Warcraft, not Warcraft 3.
You have to make sure you are running it with administrator privileges.
Warcraft 3
In Warcraft 3, you can equip items by selecting your hero and opening your inventory, which is displayed as a grid. To equip an item, simply click on the item in your inventory and drag it to one of the available item slots, or right-click the item to automatically equip it if the slot is free. Items can also be dropped or transferred between heroes and units in your control by dragging them to the desired target. Remember that only heroes can equip certain items, while units have their own inventory limitations.