The main difference between a manual spice grinder and an electric spice grinder lies in their operation and convenience.

A manual spice grinder typically consists of a container or a bowl with a grinding mechanism, such as a rotating blade or a burr grinder, and a handle or a crank. To use it, need to manually turn the handle or crank to grind the spices. Manual spice grinders are usually compact, portable, and easy to clean. They give you more control over the grinding process, allowing you to adjust the coarseness or fineness of the spices according to your preference. However, grinding spices manually can require some effort and time, especially if  have a large quantity of spices to grind.

An electric spice grinder is powered by electricity and typically has a motor that spins the grinding blades. It offers convenience and speed, only need to press a button to start the grinding process. Electric spice grinders are generally larger in size and have a higher capacity, making them suitable for grinding larger quantities of spices at once. They are ideal for those who frequently use ground spices in their cooking or baking.