The words teams, teems sound the same but have different meanings and spellings. Why do teams, teems sound the same even though they are completely different words?
The answer is simple: teams, teems are homophones of the English language.
Plural form of team.
Third-person singular simple present indicative form of team.
Third-person singular simple present indicative form of teem.
Definitions 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.