Understanding 'Last Platform Change' for E-Commerce Technology

hi guys - I got a list of companies that are using a special technology for there e-commerce platform. This list is already 1 year old, so I wanna enrich the info "last platform change" to assume that those companies have already installed the latest version of technology (I am interested in the companies that are still using the old version). What exactly does the enrichment "last platform change" means. Is it about a certain technology or can it just be a regular update like uploading new product/ pictures etc. - any experiences here?