The words choir, quire sound the same but have different meanings and spellings. Why do choir, quire sound the same even though they are completely different words?
The answer is simple: choir, quire are homophones of the English language.
sing in a choir
sing in a choir
the area occupied by singers; the part of the chancel between sanctuary and nave
the area occupied by singers; the part of the chancel between sanctuary and nave
a quantity of paper; 24 or 25 sheets
To prepare quires by stitching together leaves of paper.
A book, poem, or pamphlet.
A set of <xref>leaves</xref> which are <xref>stitched</xref> together, originally a set of four pieces of paper (eight leaves, sixteen pages). This is most often a single <xref>signature</xref> (i.e. group of four), but may be several <xref>nested</xref> signatures.
Definitions from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved., from Wiktionary, Creative Commons Attribution/Share-Alike License. and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.
If they are spelled the same then they are also homographs (and homonyms); if they are spelled differently then they are also heterographs (literally "different writing").