The words holm, hom, home sound the same but have different meanings and spellings. Why do holm, hom, home sound the same even though they are completely different words?
The answer is simple: holm, hom, home are homophones of the English language.
Chiefly British An island in a river.
A Middle English form of home.
A Middle English form of hem, obsolete objective plural of he. See he.
Same as homa.
A place where one lives; a residence.
The physical structure within which one lives, such as a house or apartment.
A dwelling place together with the family or social unit that occupies it; a household.
An environment offering security and happiness.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition, from The Century Dictionary and Cyclopedia 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").