A single piece of information is known as a value.
hello
A single piece of data is called a datum.
Galley's
A coiled piece of DNA is called a plasmid, found in prokaryotic cells.
A value
A single 'piece' of sand is called a 'grain'.
The common term for a single mosaic piece it tessera, but can also be called abaciscus or abaculus. Each piece is made of a single small tile, which is usually cube shaped. Tesseras are usually made from clay, ceramic, stone, glass, or mirror.
Your wife's sister is called your "sister in-law".
A single piece of baggage is either just ONE suitcase or item.
A bill. After it goes through the proccess of being ratified by the majority in the House and the Senate, and has the President's approval does it become a law, or piece of legislation
An essay is a piece of writing on a single subject that presents a writer's argument or opinion in a structured format with an introduction, body paragraphs, and a conclusion. It is typically focused on exploring a specific topic in depth and providing analysis or interpretation.