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