Can anybody give me an understandable definition of a Tensor...?

.....And also tell me if there is any difference between a Tensor and a Metric tensor; and what all the different tensors mean.....i.e. Herman/Weyl Tensor, Riemann metric tensor, Ricci tensor.

How many different tensors are there and what conditions make one tensor different from another?
Do the properties of a tensor change when computed in higher dimensions? If so...how? Do higher order matrices apply?

Can tensors be quantized if vectors can be quantized?

An answer to any one of these questions would be highly appreciated.

Thanx in advance,
Mark