Licensing an image is a legal decision dressed up as a download button. This site sets out how commercial stock photography licensing works in practice, which licence suits which use, and where the common and expensive mistakes are made.
Most commercial libraries sell two broad kinds of licence. A royalty free licence is paid once and then permits repeated use within stated limits, which usually cover website use, print below a certain run, and internal material. A rights managed licence is priced for a specific use, in a specific place, for a specific period, and costs more because it can carry exclusivity. The names are unhelpful: royalty free does not mean free, and rights managed does not mean more permissive.
The editorial marking is the one to read carefully. An image marked editorial may be used to illustrate news or commentary, but not to advertise. Those images typically show identifiable people, private property, branded products or trademarks without the releases that commercial use requires. Using an editorial image on a product page is one of the most common licensing errors, and it is also one of the easiest for a rights holder to find.
Extended licences cover the uses a standard licence excludes: putting an image on something for resale, using it in a template that other people will redistribute, or exceeding a print run. If a design is going to be sold rather than merely published, the standard licence is usually not enough.
Attribution and record keeping deserve a routine. Some licences require a credit and some do not, but recording the licence for every image is worth doing regardless. Keep the invoice, the licence identifier and the date alongside the file. Libraries change their terms, subscriptions lapse, and the question of what was permitted at the time is answered by the record rather than by memory.
Subscriptions and credit packs differ in a way that matters for planning. A subscription usually allows a set number of downloads per period and the right to keep using what was downloaded while the licence stands. Credits generally do not expire as quickly but cost more per image. For a site that needs images occasionally, credits waste less; for regular publishing, a subscription is cheaper per image.
The practical summary is short. Read whether the image is editorial or commercial before anything else. Check for a model release if a person is recognisable. Buy an extended licence if the work will be resold. Keep the paperwork. None of it takes long, and it removes almost all of the risk that stock photography carries.
One further habit prevents most disputes: check the licence again when a use changes. An image licensed for a blog post and later moved onto packaging, an advertisement or a product for sale has moved outside what a standard licence covers, and the fact that it was licensed correctly the first time does not carry over. The same applies when a site changes purpose, for example when a personal project starts selling something. Reviewing the images on the pages that changed takes very little time, and it catches the situation where a perfectly legitimate download from two years ago has quietly become an unlicensed commercial use through nothing more than the site growing up.