Not if it was properly installed.

I really don't know what was used to stick it down. I suppose mortar was used and then it was grouted in between.

Define "easy". Chances are good if it was done properly there will be an additional layer of plywood on top of the subfloor to give the floor additional rigidity. If that's the case you can usually pry up that layer with the tile stuck to it, assuming it was nailed and not also glued down. You can then replace that layer and put new tile over it. That's relatively easy. If your tile is laid on a "mud job", a 1-2" thick mortar bed, that might or might not nave an additional layer of underlayment you can pry up, and might or might not have been put down over a separation barrier (typically roofing felt in older work). If there is a felt layer you can usually break up the tile and mortar with a sledge hammer, wrecking bar, or other tools of destruction and get it out reasonably easily (but working up a sweat in the process). If its firmly stuck to the subfloor things quickly become more difficult. Removing and replacing the subfloor turns into a pretty good day's work, but doesn't take a whole lot of skill or finesse, so depending on your scale may meet your criterion of easy. Any of the above is easier than trying to pry the tile up off the substrate in a way that you can apply new tile or other flooring over it.

And, as noted above, you can tile over existing tile if it's in good shape and firmly attached.

The best tool for removing tile is the telephone. Takes very little effort really.

Take some pictures and post on the John Bridge Tile Forum. Good guys and gals there.

We took up the tile in our foyer - it was a lot of work. There was plywood screwed to the subfloor, and it was far easier to replace the plywood than try to get the mortar cleaned off.

Good luck!

Rotary hammer set on hammer only and tile chisel is the easiest way, or pry bar and hammer if you want the hard way. Sometimes you can get away with just a prybar if it wasnt installed correctly (not back buttered).

Oh and hearing and eye protection are a must. Gloves and long sleeves are highly recommended, tile that breaks and flies can be sharp and could make for an ER trip and stitches involved.