Is you laptop or desktop running slow? Then it may not be the processor. We have done many upgrades to processor, but the HDD is same 5400 rpm or 7200 rpm. So even if you get the latest core i7 processor, you won’t get the best performance.
You may ask why? Then my answer will be, What if we make bed with 3 strong legs & 1 weak leg & there will be 10 people standing on it? Won’t it break? Same thing happens with your system. When you have a poor slow HDD & the best processor, you still get a system which is slower or like the the weaker bed for only one weak leg.
When we use the system, it reads & writes data from & to the HDD or hard disk drive. With HDD, it reads & writes super slow. While with SSD, it reads & writes ultra super fast.
HDD has more power consumption, while SSD has too low power consumption which helps to save battery life if used in laptops.
HDD have mechanical parts which leads to broken HDD at any time. SSD don’t have any mechanical parts which leads to longer life of SSD.
From price point of view SSD costs more than HDD. But if you see the lifespan of SSD vs HDD, then you get back with the SSD.