The difference between Cello and String

Cello as a noun (musical instruments):

A large stringed instrument of the violin family with four strings, tuned from lowest to highest C-G-D-A, and played with a bow, also possessing an endpin to support the instrument's weight.

Cello as a noun:

cellophane

String as a noun (countable):

A long, thin and flexible structure made from threads twisted together.

String as a noun (uncountable):

Such a structure considered as a substance.

String as a noun (countable):

Any similar long, thin and flexible object.

String as a noun:

A thread or cord on which a number of objects or parts are strung or arranged in close and orderly succession; hence, a line or series of things arranged on a thread, or as if so arranged.

String as a noun (countable):

A cohesive substance taking the form of a string.

String as a noun (countable):

A series of items or events.

String as a noun (countable):

The members of a sports team or squad regarded as most likely to achieve success. (Perhaps metaphorical as the "strings" that hold the squad together.) Often first string, second string etc.

String as a noun (countable):

In various games and competitions, a certain number of turns at play, of rounds, etc.

String as a noun:

A group of racehorses kept by one owner or at one stables.

String as a noun (countable, computing):

An ordered sequence of text characters stored consecutively in memory and capable of being processed as a single entity.

String as a noun (music, countable):

A stringed instrument.

String as a noun (music, usually in plural):

The stringed instruments as a section of an orchestra, especially those played by a bow, or the persons playing those instruments.

String as a noun (in the plural):

The conditions and limitations in a contract collectively.

String as a noun (countable, physics):

The main object of study in string theory, a branch of theoretical physics.

String as a noun (slang):

Cannabis or marijuana.

String as a noun:

Part of the game of billiards, where the order of the play is determined by testing who can get a ball closest to the bottom rail by shooting it onto the end rail.

String as a noun:

The points made in a game of billiards.

String as a noun (billiards, pool):

The line from behind and over which the cue ball must be played after being out of play, as by being pocketed or knocked off the table; also called the string line.

String as a noun:

A strip, as of leather, by which the covers of a book are held together.

String as a noun (archaic):

A fibre, as of a plant; a little fibrous root.

String as a noun (archaic):

A nerve or tendon of an animal body.

String as a noun (shipbuilding):

An inside range of ceiling planks, corresponding to the sheer strake on the outside and bolted to it.

String as a noun (botany):

The tough fibrous substance that unites the valves of the pericarp of leguminous plants.

String as a noun (mining):

A small, filamentous ramification of a metallic vein.

String as a noun (architecture):

A stringcourse.

String as a noun (dated, slang):

A hoax; a fake story.

String as a verb (transitive):

To put (items) on a string.

String as a verb (transitive):

To put strings on (something).

String as a verb (intransitive):

To form into a string or strings, as a substance which is stretched, or people who are moving along, etc.