The main difference between SSD (Solid State Drive) and HDD (Hard Disk Drive) storage technologies lies in their underlying mechanics and performance. SSDs utilize flash memory to store data, providing significantly faster read and write speeds compared to HDDs, which use spinning disks and mechanical arms for data access. This translates to quicker boot times, faster file transfers, and improved application load speeds with SSDs. Additionally, SSDs are more durable due to the absence of moving parts, while HDDs remain more cost-effective for larger storage capacities.