The words wood, would sound the same but have different meanings and spellings. Why do wood, would sound the same even though they are completely different words?
The answer is simple: wood, would are homophones of the English language.
Used or suitable for cutting, storing, or working with wood.
The secondary xylem of trees and shrubs, lying beneath the bark and consisting largely of cellulose and lignin.
This tissue, often cut and dried especially for use as building material and fuel.
A dense growth of trees or underbrush covering a relatively small or confined area. Often used in the plural.
Used to express desire or intent: She said she would meet us at the corner.
Used to express a wish: Would that we had gone with you!
Used after a statement of desire, request, or advice: I wish you would stay.
Used to make a polite request: Would you go with me?
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition 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").