SSD hosting is significantly faster than traditional hosting due to the huge difference in I/O speeds.
An SSD is similar to a USB memory stick where all of its data are stored in microchips. This means that it can access any of its data instantly regardless of which chip the data is stored on.
Meanwhile, an HDD uses a mechanical arm to read and write its data, similar to a record player. As you can imagine, an HDD will read and write data a lot slower since it needs to move its mechanical arm around all the time. It gets much worse when the data is stored at random locations on the disk.
SSD hosting can be up to 30X faster than traditional hosting.