The words presence, presents sound the same but have different meanings and spellings. Why do presence, presents sound the same even though they are completely different words?
The answer is simple: presence, presents are homophones of the English language.
Immediate proximity in time or space.
The state or fact of being present; current existence or occurrence.
The area immediately surrounding a great personage, especially a sovereign.
A person who is present.
Plural form of present.
Third-person singular simple present indicative form of present.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition, 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.