The ACCESSIBILITY of a member or a TYPE is specified using ACCESS modifiers. The four main access modifiers are given as follows:

1. public

The members that are public can be accessed without restrictions. So this is the most permissive accessibility modifier.

2. protected

The members that are protected can be accessed in the class in which they were declared or from any derived classes that were derived from the class that declared the member in question.

3. internal

The members that are internal can only be accessed from the files that are in the same assembly. Any class or a class member can be declared as internal.

4. private

The members that are private can only be accessed in the class or structure in which they were declared and not outside. So, this is the LEAST permissive accessibility modifier.

There are six accessibility levels that can be specified from the above access modifiers. These are given as follows:

• public

There is unrestricted access.

• protected

The access is restricted to the containing class or the various classes and types that are derived from the containing class.

• internal

The access is restricted to the files that are in the same assembly.

• protected internal

The access is restricted to the various classes and types that are derived from the containing class and the files that are in the same assembly.

• private

The access is restricted to the containing class or type.

• private protected

The access is restricted to the containing class and types that are derived from the containing class in the same assembly.