Named methods can be assigned to delegates with matching signatures:

public static class Example
{
    public static int AddOne(int input)
    {
        return input + 1;
    }
}

Func<int,int> addOne = Example.AddOne

Example.AddOne takes an int and returns an int, its signature matches the delegate Func<int,int>. Example.AddOne can be directly assigned to addOne because they have matching signatures.