Definition - What does Access Specifier mean?
Techopedia explains Access Specifier
Programmers define code elements and pieces of data as public or private for various reasons. A public status is good for code elements that are valuable to various outside functions, but for items that can be easily changed, where those changes affect the solvency of the code, a private status can be helpful. There are other pros and cons to private and public access specifiers, including errors and glitches after alterations of public items, and run-time errors related to inaccessible private items.