A class can have a set of some data in it.
These are called member fields.
Let us add one member field to our class and make it of type char:
class MyClass { char c; };
Now our class has one data member field of type char called c.
Let us now add two more fields of type int and double:
class MyClass { char c; int x; double d; };
Now our class has three member fields, and each member field has its name.