A HDD can get a speed bonus from having data in sequential order on the platter itself. Because the platter is spinning if data is stored in broken up bits (Fragmented) the platter needs to spin more often and the read write head also has to move to get the data off the platter. That increases read speed, and more importantly increases access time (the amount of time it takes for the data to be located and accessed).
An SSD has no physical moving parts so its able to instantly pull up the correct information because no spinning platter or moving read/write head. Its all instant (Kinda). Still limited by throughput but the access time is Zero for all intensive purposes.