• Letter দুই প্রকার। যথা - i) Informal Letter : যা ব্যক্তিগতভাবে আত্মীয়স্বজন বা বন্ধুবান্ধবের কাছে পাঠানো হয়। ii) Formal Letter: Official বা Business সংক্রান্ত চিঠিপত্র। যেমন - Application, Memorandum ইত্যাদি। - সুতরাং, “Memorandum” is one kind of - Formal Letter.
• Memorandum 1. a short note written to help one remember something or remind one to do something/ a record of events or observations, esp. one for future use. 2. an informal written communication, as from one department to another in an office 3. In diplomacy - a summary or outline of a subject under discussion, reasons for or against some action, etc. 4. In Business - a statement, made by the consignor, of the goods and terms of a consignment sent with the privilege of return. 5. Law - a short written statement of the terms of an agreement, contract, or transaction.