Neural networks can approximate theoretically an arbitrary nonlinear process to any desired degree of accuracy.

全句可译为：
Neural networks (NNs) can approximate theoretically an arbitrary nonlinear process to any desired degree of accuracy; therefore, NNs are very applicable to function approximation and prediction.

Using Accuracy vs. Precision:
Accuracy refers to the closeness of a measured value to the actual value.

Precision refers to the closeness of two or more measurements to each other. Precision is independent of accuracy; you can be very precise but inaccurate.