What is the difference between expert systems and artificial neural networks $($ANNs$)?$

Expert systems are used for poorly structured problems, whereas artificial neural networks are used for well$-$structured problems.

Expert systems use if$-$then$-$else rules, whereas artificial neural networks use patterns.

Expert systems can supply explanations for solutions, whereas artificial neural networks cannot.

Expert systems create models based on input and output, whereas artificial neural networks create models based on patterns.