What are the differences between a spring washer and a flat washer, and how do these variances impact their respective functions in mechanical applications?

A spring washer is designed to provide tension and prevent loosening of fasteners, while a flat washer is used to distribute the load and protect the surface. The spring washer's ability to maintain tension makes it ideal for applications where vibration or movement is present, while the flat washer is better suited for general purpose use where load distribution is the primary concern.