Chess Opening Theory/1. e4/1...c5/2. d4/2...cxd4/3. Nf3

This aims to transpose into normal lines. After Nxd4, a normal open Sicilian will be reached. If Black tries to prevent this with 3...e5, White will reach a good Smith–Morra with 4. c3. Therefore, Black does best to allow Nxd4.