IP65 and IP66 are ratings that indicate the level of protection of an electronic device or tool. The abbreviation "IP" stands for "Ingress Protection" and refers to the degree to which the device is protected from external factors.

The IP system specifies the level of protection of a device with a number ranging from 0 to 6. Each of these represents the level of protection of the device from a particular external factor. The first number indicates the level of protection against solid objects, such as dust and fingers, while the second number indicates the level of protection against liquids, such as water.

An IP65 rating means that the device is dust tight and has a high level of protection against water jets. This makes the device suitable for use in outdoor environments and applications where it may be exposed to dust or water.

An IP66 rating means that the device is dust tight and has a high level of protection against powerful water jets. This makes the device suitable for use in outdoor environments and applications where it may be exposed to dust or water, and is more resistant to water than a device with an IP65 rating.

It is important to consider the IP rating of a device when selecting it for a specific application, as it will help determine whether the device is suitable for the intended environment and can be used safely.