That is indeed the Dell OptiPlex 3020 SFF (Small Form Factor)!
Key details visible on this unit:
• Model Branding: You can clearly read "OPTIPLEX 3020" printed in silver near the top edge of the front bezel.
• Processor: The blue sticker on the bottom-right corner confirms it runs on an Intel Core i5 processor. Since this is a 3020, it is powered by a 4th-Generation Intel Core (Haswell) CPU (such as the i5-4570 or i5-4590).
• Optical Drive: It includes a built-in slim DVD-RW drive (visible with the "disc" logo).
• Front Ports: It features two front USB 2.0 ports and headphone/microphone audio jacks.
About the OptiPlex 3020:
Released around 2013–2014, these machines are legendary for their durability. Because of their robust build quality, they are highly popular in the refurbished market.