what data type is stored in post array

what data type is stored in post array

Please bear with me as I'm a newbie, but none of my googling efforts have yielded a straight answer as to what data type is held in the post array. When data is submitted to the server via the php post array, is it submitted as a string? Again, seems like a simple google search would give me the answer to this, but I can't find anything. Also, I have searched through the topics on jquery before posting this question, as I would like to avoid creating duplicate questions. Many thanks for your time. Jonathan