Why would you like to disable cache?
Well probably you wouldn’t. Especially not when your store is already live an fully functional. But on developing stage, disabling the cache would make it possible for you to immediately test and control the fluent changes you are constantly applying to your theme, locale files or scripts. Not disabling cache in this case will cause a huuuge frustration. Not to mention an almost irrepressible desire to bang your head against the nearest break wall! Not at all recommended, and may be avoided quite easily like so:
In the back office, go to system => configuration => cache management.
Check marked the checkboxes near layouts, block HTML Output and Translations
From the top right hand side drop down menu, select ‘disable’
When the page refreshes, notice that for each of these lines, the status has changed to red, with the message ‘disabled/inactive’.
Now go ahead, refresh your frontend, your changes are there, see? Go grab a glass of water, sit down and relax for a while.