Hi,
A web cache is a mechanism for the temporary storage (caching) of web documents, such as HTML pages and images, to reduce bandwidth usage, server load, and perceived lag. A web cache stores copies of documents passing through it; subsequent requests may be satisfied from the cache if certain conditions are met.
To disable the Joomla cache, you have to go in the global configuration and disable it, you have too to unpublish the joomla cache plugin. It's possible that your template or other extensions manage the cache too on your website, thanks to disable them.