What is the minimum shares to buy in NYSE?

Could you please elaborate on the minimum share purchase requirements for trading on the New York Stock Exchange (NYSE)? I'm curious to understand if there's a specific number of shares one must acquire to engage in trading, or if it varies depending on the security being traded. Additionally, are there any other financial or account requirements that need to be met before making a purchase? Understanding these parameters would help me make informed decisions regarding my investment strategy on the NYSE.