Typecasting is the action of defining data (in this case people) depending on how it’s to be processed.

Explicit typecasting is the rigid defining of data in these types and can only be processed as that type of data.

Implicit typecasting will transpose data between types interchangeably depending on how the data is being processed.

A more comprehensive explanation would require a class on data structures.

This meme is nonsense even if you are a programmer. Explicit typing does not limit you to two options, it just means all values need to be typed.