The words scend, send sound the same but have different meanings and spellings. Why do scend, send sound the same even though they are completely different words?
The answer is simple: scend, send are homophones of the English language.
To heave upward on a wave or swell.
The rising movement of a ship on a wave or swell.
send for To request to come by means of a message or messenger; summon.
To cause to be conveyed by an intermediary to a destination: send goods by plane.
To dispatch, as by a communications medium: send a message by radio.
To direct to go on a mission: sent troops into the Middle East.
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").