An external solid state drive (SSD) is a portable device that can store and transfer data faster and more reliably than a traditional mechanical hard drive (HDD). SSDs have no moving parts and use flash memory chips to store data, making them more shock-resistant, power-saving and quiet. The main advantage of SSD is speed, it can read and write data much faster than HDD, thus shortening the time of system startup, application loading and file transfer. The speed of an SSD also depends on the type of connection it uses, such as USB 3.0, USB 3.1, or Thunderbolt 3. Another benefit of SSD is portability and compatibility. It is usually smaller and lighter than HDD, making it easier to carry and use. You can use SSDs to expand the storage space of your laptop, tablet, phone, or game console, as long as they have compatible ports. Some SSDs also have biometric locks or encryption features to protect your data from unauthorized access. SSDs work well for storing and transferring large amounts of data, such as photos, videos, music, games, and documents. However, it also has some disadvantages, such as higher price, smaller capacity, shorter life, etc. In summary, an external SSD is a fast, reliable, and portable device that can store and transfer data more efficiently than a traditional mechanical hard drive. However, it also has some drawbacks that you need to weigh up. If you want a storage device that offers you speed, convenience, and security, an external SSD might be a good choice.