Are the terms Conservatorship and Guardianship synonymous? If not what is the difference.

There are some nuances, and they may be treated differently by individual states.

In general, my search of an online legal dictionary yielded --

A conservator is a person responsible for maintaining the person and property of an incompetent.

A guardian is a person responsible for maintaining the person and property of an incompetent or a minor.

To add to John's answer, you can be a guardian of a person and not of property. Some states are very specific. Oklahoma has a handbook that explains both. Unfortunately, I do not remember the title. When my husband was guardian for his mother, we followed the handbook. It was more helpful than our attorney.