Page descriptions show up on site page, how do I modify them?

On my website that I didn’t originally create, there are quotes located below the header and above the page’s content. I need to add more quotes to new pages and change the old page. I’ve spent hours tirelessly searching the code for this data. I searched in the database and xml file and was able to find this code under postmeta and page_desc, but I cannot find any of this in the php file. I know if I found the php file will this content, I could change it, right? I’m tired of searching and I need some serious help. Website source code says its caption_desc, and when I highlight the words they seem to be broken up or not real words, but pictures. The media gallery doesn’t have any of these photos though, so I don’t know. Please help me find where to modify page_desc meta values.