C#: What is the difference between LINQ and SQL?

1// LINQ
2var result = users
3    .Where(u => u.Age > 18)
4    .Select(u => u.Name)
5    .ToList();
6
7// SQL
8var result = context.Users
9    .FromSqlRaw("SELECT Name FROM Users WHERE Age > 18")
10    .ToList();