Speed performance is critical in modern day applications. Most of the times your application may have to make requests to an endpoint/server to get some data. Or your application may frequently request a specific dataset. Depending on the size of your dataset a long with other things like query database and network speed, the speed at which your application can fetch certain data to display to users may get slower over time (as data increases). This is where caching comes in handy and can dramatically improve your application's speed.
Chances are you've heard about or used URL shortening services like bitly, and tinyurl. These services allows you to enter long (and quite ugly) URLs and in turn gives you a very short (more appealing) link which you can use instead of the long URL. Shorter links takes up less space and are easier to share and type