An application-specific instruction-set processor (ASIP) is like a toy that is DESIGNED to do one very specific thing. Imagine a toy truck that is designed to pick up and move only red blocks. You can't use it to pick up other objects or move different colored blocks, but it's really good at what it does. Similarly, an ASIP is like a toy computer processor that is designed to handle a specific task or set of tasks really well, but isn't as good at other tasks as a general-purpose processor.
For example, let's say you want to design a processor that can do fast video compression. A general-purpose processor like the one in your computer or phone can do this task, but it may not be the best at it. An ASIP designed specifically for video compression might have built-in instructions and hardware optimized for that task, which means it can do it faster and more efficiently than a general-purpose processor. It's like having a toy truck that is specifically designed to pick up only red blocks, and it does it faster than any other toy truck you have.
The downside of ASIPs is that they are not as flexible as general-purpose processors. You can't use an ASIP designed for video compression to do other tasks like playing music or running a web browser. But if you need a processor that is really good at a specific task, an ASIP might be just what you need.