| Full Form |
HDD stands for Hard Disk Drive. |
SSD stands for Solid State Drive. |
| Components |
HDD contains moving mechanical parts, like the arm. |
SSD does not contains, mechanical parts, only electronical parts like ICs. |
| R/W Time |
HDD has longer R/W time. |
SSD has shorter R/W time.. |
| Latency |
HDD has higher latency. |
SSD has lower latency. |
| I/O operations per second |
HDD supports fewer I/O operations per second. |
SSD supports more I/O operations per second. |
| Fragmentation |
HDD has fragmentation. |
SSD do not has fragmentation. |
| Weight |
HDD is heavier in weight. |
SSD is lighter in weight. |
| Size |
HDD is larger in size. |
SSD is more compact in size. |
| Data Transfer |
In HDD the data transfer is sequential. |
In SSD the data transfer is random access. |
| Reliability |
HDD is less reliable due to possibility of mechanical failure, like head crash and susceptibility to strong magnets. |
SSD is more reliable. |
| Cost |
HDD is cheaper per unit storage. |
SSD is costlier per unit storage. |
| Time of Release |
HDD is older and more traditional. |
SSD is newer to use. |
| Noise |
HDD can produce noise due to mechanical movements. |
SSD does not produces noise. |
