What is the difference between enterprise architecture and solutions architecture?

Enterprise architects take a strategic approach to optimizing the interplay between a large number of applications within an enterprise portfolio, while solutions architects take a deep, tactical approach to a narrower band of applications.

to simplify the answer..
solution architecture is building the details of a puzzle piece that fits in the bigger picture which is enterprise architecture..
when working on a solution design you are figuring out how a specific tool will function and provide the outcome you expect out of it..
but when working on an enterprise level architecture you are building an enterprise strategy a holistic road map to how all bits and pieces fit together..