The license is not checked when accessing via IP or internal local name (eg. localhost or the name of local server/machine). Note that if the internal hostname resolves to non-local IP, then the license will be checked in this case hostname is considered like a domain.
By the way by local I don’t mean local network or intranet. Local means local machine in this context. So the license is not checked when the browser and server is on the same machine.
Professional License allows using the product on one single domain which you control, and its subdomains which you control, without restrictions based on server, CPU, or core count. The license key is generated with a wildcard domain (e.g. *.contoso.com) and during runtime the HOST header is checked against this wildcard domain. The domain is not required to be public-facing, internal domains/hostnames (e.g. myserver) are also accepted. Note that developing or running locally (eg. localhost or 127.0.0.1) is not restricted, the license domain is checked only when you deploy/publish. This license does not allow using the product in non-web applications (i.e. console or dektop apps) as it's bound to one single domain/hostname; consider Enterprise License (or higher) for that purpose.
Enterprise License grants enterprise-wide rights (including subsidiaries), but can also be purchased by an individual. Redistribution is restricted to bespoke, custom software, i.e. internal software that your organization uses. This license allows using the product on multiple domains and their subdomains which your organization owns. This license allows using the product in non-web applications (i.e. console or dektop apps).
Distribution License is the license you need if you wish to sell or distribute a product which contains this product. This license is very similar to the Enterprise License, but does not restrict redistribution and sub-licensing to bespoke, custom software. This license allows using the product on multiple domains and their subdomains which your organization and your customers owns.