The dictionary defines a member as 'a constituent part of a whole'.
In C#, there are class members and struct members. I.e. parts of a class, and parts of a struct.
A member is a field, property or method within a class or struct.
A field is a type of member that is accessed directly within the class or struct.
An example:
class Test // a class
{
private string _firstName; // a member. a field.
public string FirstName // a member. a property
{
get { return _firstName; }
}
public void Print() // a member. a method
{
Console.WriteLine("Hello " + _firstName);
}
}