You can replace the HDD with a 2.5" SATA SSD or add an M.2 SSD in addition to the HDD. Either SSD would be much faster than the HDD. 
Have just purchased the above PC and it came with a HDD instead of a SSD Before setting it up I was wondering if it would be worth buying a SSD and installing that in place of or in addition to the 500GB HDD. I haven't received it yet to try it out but I was worried about it being too slow for the person I brought it for. 
Refurbished OptiPlex 7060 Micro Intel i5 8500T with HDD