White Label Solution in digital marketing is a brand-less (blank) version of a software, or platform that can be used for re-sale or re-use with ones own branding on it.
Wikipedia defines White Label Product as: Some websites use white labels to enable a successful brand to offer a service without having to invest in creating the technology and infrastructure itself. Many IT and modern marketing companies outsource or use white-label companies and services to provide specialist services without having to invest in developing their own product.