Commercial vs Portrait Photography
Commercial photography is involves the taking of photographs for commercial uses (product shots, head-shots, etc). These photographs are often used for the promotional marketing of a business including website placement, product previews, and business card/marketing material images. Typically the contract is between a company and the photography business and are seeking for a commercial usage license. Commercial licenses are typically for usage as businesses as seeking to have high-resolution digital files for use in marketing.
Portrait photography is for personal use by a private individual. These are typically to document a time in their life i.e. weddings, family sessions or boudoir, not for high-traffic viewing.