"Eros" is the Greek word for desire. "Cupid" is the Latin word for desire. So, the Roman gods are not really different at all, so much as cultural transplants with the names translated.
And Aphrodite is the goddess of Love, Beauty, Pleasure, and Procreation. Her domain covered love in all it's aspects, including platonic, or 'pure' love.
Eros purview was focused on erotic love or desire - in fact that's where the word erotic comes from.
In the love department, Aphrodite was the major and more venerated deity.