EF Core is a modern object-database mapper for .NET. It supports LINQ queries, change tracking, updates, and schema migrations.

Since the article didn't explain. They're inserting an abstraction layer in front of the database. You as a user will probably never notice a change.

I'm excited to see what the refactoring will allow the dev team to produce. Technical debt is a really good thing to clean up but there might be some growing pains in the mid term.