In general, White Label is a record that's released before the actual release of something especially a music album. However, when it comes to White-Label in the Search Engine Optimization, then it is a service that is provided to its clients without showing its name.
For example, if you are a digital marketing company and to manage your big number of clients, you hire a company to perform the marketing.
Any SEO company that uses the label of white-label in its name, then it means, they offer you a complete liability to re-brand their services such as using your name in credits.
A White Label Search Engine Optimization allows you to do SEO services on your behalf and lets you generate the reports, by using your own brand name in the reports.
White label SEO providers are very expert in doing digital marketing hence they can meet your client’s requirement in the best way.
Now, that company often called as white-label SEO reseller, will work on your behalf and won’t show its name in the SEO reports and you are allowed to use your name and tell your clients that complete SEO is done by you.