What does AsEnumerable() do for Dbset classes

Question

So I'm trying to retrieve data from a database through a database context, but when I'm trying to filter with only Where(), it throws an error

Here's the code:

using (var context = new DbContext())
{
var adults = context.People
//.AsEnumerable()
.Where(x => x.Age >= 18);
}

Answer 1

AsEnumerable down casts to IEnumerable and causes the following query operators (.Where...) to bind to an enumerable operator instead.

This makes subsequent query execute locally.

Answer 2

DavX, thank you