Kya Regulation aur Memorandum mein difference hai?

Mujhe thoda confuse hai, sir. Maine socha tha ye dono ek jaisi hi cheezein hain, lekin kuch lectures mein Professor-ne regulation ka reference liya, to kuch places mein memorandum ka. Main sochta hoon, kya regulation sirf kanoon hi hai, aur memorandum uska description ya conditions hote hain? Aur kya koi example hai jiska regulation aur memorandum dono alag-alag hote hain? Maine socha tha Regulation of the Board of Directors ka koi connection hoga, lekin koi specific example na pata chala. Kuch example ya explanation koi bata sakta hai?