What is the "tensor" in TensorFlow?

In TensorFlow, a tensor is a multidimensional array used to represent data in a machine learning model. It generalizes scalars (0D-array), vectors (1D-array) and matrices (2D-array) to higher dimensions.

But don't be fooled. A true mathematical tensor has much more going on behind the scenes, being multilinear maps with specified transformation rules. 

A TensorFlow tensor is a looser construct than that.

Describing Einstein's General relativity mathematically involves the use of tensors of the math variety.