What is difference between meter socket adapter and panel surge arrester?

A meter socket adapter is used when solar energy is required to be fed back to the grid from a home owners solar array system. The adapter is on the line side of the service between the utility meter and the utility meter base.

A meter base surge protector is a device to stop surging from lightning strikesfrom the grid from entering your home. This device is also connected to the line side of the service between your utility meter and the utility meter base.