Filipino is a term that originally referred to the Spanish population who were born and settled in the Philippines. During the nationalization movements of the late 19th century and after the revolt and independence from Spain in 1898, it came to refer to the general population.
Ang filipino "subject" ay mayroon kang maraming malalaman tulad ng Uri ng Liham.
A letter is a written message from one party to another. Letters are usually intended to be received by someone far away. Before widespread availability of typewriters and computers, letters were always written by hand. Nowadays, that is still done, mainly for informal letters. The term letter is sometimes used for e-mail messages with a formal letter-like format.
There are many kinds of letter like letter for your Barangay Chairman, Letter for asking an subscription, Letter who is inviting someone and Letter asking for information about a thing. You can use it wherever you might go.