If a web designer is building a new website for you, you probably experienced the following issue: Some changes had been made by your developer on the site, but when you load the website you can't see the changes. Due to this, co-working and co-ordination can be exhausting and sluggish. If you visit other public pages you normally don't notice this problem, because as a visitor you don't know that any changes, like a new logo, have been made on another company's website. You will see the changes when the cache "is full" and old saved data will be replaced by new ones. But if its your own website, you might wonder why changes are not visible yet. And in the development process, you want to be up to date with the current state of course. As a website user, you should clear your browser cache regularly.
The cache, in computing, is a place where data is stored temporarily. As a user, you often use the cache when using a web browsers. When you open a website, its contents are saved on your computer. As a website visitor, you don't notice this process, because the saving is done in the background. In the web, this enables faster rendering and shorter loading times. The data which is stored in the cache are HTML files, stylesheets, scripts, images and other media files. If you navigate on a website back and forward, the browser doesn't have to download all the data again but gets the required files from the cache. The browser compares superficialy what has been changed since the last visit so that only new files are downloaded.
The cache should be cleared regularly for several reasons. Depending on your settings, the cache can grow quite big and use a lot of disk space on your computer. And that's even if you don't visit some pages ever again. The more information that is saved in the cache, the slower your computer will be browsing the web. Deleting the cache data helps to troubleshoot, helps to increase the loading time of web pages and increases the performance of your computer.
If the browser doesn't load the new version of the site, even if there have been changes on the site since the last visit, the cache can cause issues with the view. The website might look like it has not been fully loaded or is wrongly formatted. Maybe you already wondered why a website is showing outdated contents, despite it having been updated. That's probably because of the cache. Sometimes data, which is stored in the cache prohibits loading of up-to-date contents. When you delete the stored cache data, the new version can be retrieved. In many website related issues, the cache is the root of all evil. That's why your web developer/web designer or IT-Support first asks you to clear the cache before investigating further.
By the way: since the cache stores website data, you can tell from the saved information which sites had been visited in the past. Regarding privacy and data security clearing the cache could be also interesting for you.