So you are trying to decide on what tile to use for your bathroom, right? And, like any good consumer, you start reading sales information.
The two main types of tile you're most likely to run into are Ceramic and Porcelain. You'll almost aways be told that Porcelain is the better option. Sales staff will often forget to mention that it's more expensive and/or they make more money in commission when you buy it.
Porcelain - Advantage
It is one consistent color throughout. This means, if it chips, you won't be able to see it as easily. This is the most common line used by sales staff in steering you towards this product. The consistent color pattern throughout, they will tell you, makes wear and tear harder to notice.
Porcelain - Disadvantage
Cost. It ain't cheap.
Ceramic - Advantage
Cost. It's cheaper.
Ceramic - Disadvantage
Most tile is a terra cotta layer with the finish color being a second layer on top of that. If you do end up chipping the tile, most likely you will see the much darker terra cotta finish underneath.
It comes down to this -- how many tiles have you chipped in your lifetime? For me it's somewhere between none and who cares. And for that reason, I'll pick a ceramic I like, pocket the extra cash that porcelain would have cost me, and put it towards upgrading my FIXTURES and COUNTERTOPS instead.
Tiles might look nice but you're always going to win when you upgrade the products people have to touch.