What is the difference between SQL Server Compact Edition and SQL Server Express Edition?

Question

Can someone please explain what is the main difference between SQL Server Compact Edition and SQL Server Express Edition?

For what purpose I should use this or that one?

Thanks

Answer 1

This blog has everything you need, it will even give you a feature comparison.

If you don't feel like reading, SQL Server Compact is for Mobile/Embeded Apps, and Express edition is just a free scaled down SQL Server standard.

Edit A very important thing to point out as @Rup just stated is that Compact is an in memory database.