Dried shrimp are just like regular shrimp, but they have been dried out so that they last longer and can be stored for a longer period of time.
Have you ever had beef jerky? It's a similar concept. The process of drying the shrimp involves removing all the water from them. This can be done by either leaving them out in the sun or using a machine to dry them out.
Once the shrimp have been dried, they will be much smaller and lighter than before. This is because all the water has been removed. They will also be quite hard and crunchy to eat, which some people find very enjoyable.
You can eat dried shrimp on their own as a snack, but they are often used as an ingredient in cooking. Dried shrimp are commonly used in Asian cuisine, especially in soups or stir-fries.
Overall, dried shrimp is essentially just regular shrimp that has been dried out so that it lasts longer and has a more concentrated flavor.