The words analyst, annalist sound the same but have different meanings and spellings. Why do analyst, annalist sound the same even though they are completely different words?
The answer is simple: analyst, annalist are homophones of the English language.
One that analyzes.
A practitioner of psychoanalysis.
A systems analyst.
One who writes annals; a chronicler.
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.