The difference between Buzz and Drop someone a line

Buzz as a noun:

A continuous, humming noise, as of bees; a confused murmur, as of general conversation in low tones.

Buzz as a noun:

A whisper.

Buzz as a noun:

The audible friction of voice consonants.

Buzz as a noun (informal):

A rush or feeling of energy or excitement; a feeling of slight intoxication.

Buzz as a noun (informal):

A telephone call or e-mail.

Buzz as a noun (informal, preceded by {{m, the):

}} Major topic of conversation; widespread rumor; information spread behind the scenes.

Buzz as a verb (intransitive):

To make a low, continuous, humming or sibilant sound, like that made by bees with their wings. To utter a murmuring sound; to speak with a low, humming voice. To fly while making such a sound.

Buzz as a verb (colloquial):

To show a high level of activity and haste (alluding to the common simile "busy as a bee"). Often in the colloquial imperative "Buzz off!"

Buzz as a verb (transitive):

To whisper; to communicate, as tales, in an undertone; to spread, as a report, by whispers or secretly.

Buzz as a verb (transitive):

To talk to incessantly or confidentially in a low humming voice.

Buzz as a verb (aviation):

To fly at high speed and at a very low altitude over a specified area, as to make a surprise pass.

Buzz as a verb (transitive):

To cut the hair in a close-cropped military style, or buzzcut.

Buzz as a verb (archaic, transitive):

To drink to the bottom.

Drop someone a line as a verb (idiomatic):

Write and send (someone) a note or telegram.