What is the downside of clearing my cache?

The cache keeps site data, such as images, locally on your computer so that each time you visit a page the complete content of the page does not need to be downloaded. Some content is just loaded from your cache. This makes displaying frequently visited pages faster. If you delete the cache the next time you visit a previously cached site the site will be forced to download. This new download will result in a new cache being created. There is no downside other than the next visit to a site will force a download.

hot_spur wrote:

One downside is that any sites that you have stored logi info so that you automatically connect will require that you login again.

I think passwords are stored in cookies. If the OP deletes his cookies then he will loose stored data such as passwords and other identifying information. Deleting cookies will also delete site specific information such as contents of shopping carts and other actions performed on specific sites, assuming of course that the site uses cookies to store this onfo. Session variables can also be stored in cookies.

rodeamurphy wrote:

I use my computer for work on a website. I am having trouble logging into one of the sites. I have been told to clear my cache, and that will solve my problem. Is this safe and what is the downside of doing it? I am relatively new to a mac, switched from pc for this job

The cache performs the same function on PC or Apple computers.

One downside is that any sites that you have stored login info so that you automatically connect will require that you login again.