In version 2.6 WordPress introduced the captions feature which meant that when you uploaded an image, the text you entered as the ‘alt’ text, previously only visible to search engines, was now used as a caption under your image, visible to all.
I personally have found this quite annoying and should you agree, here’s a couple of ways to end the madness.
1) Permanent Caption Disabling.
The plugin I use is called, surprisingly enough, ‘Caption Disabler’. At my last check I did not find it when searching in the plugin directory within the WordPress dashboard. So you will have to download it here then upload it to your Plugins directory. It’s a very small, simple php file and will permanently remove the caption feature from future posts. Phew.