If you think of the whole system as a ‘Storefront’, which it is, then by definition all users should login at the ‘Storefront’, which is a URL you can control, with logos and content. All your clients can login here, but they might not all see the same thing.
If they are all set to see the same thing, they could be described as ‘Storefront Clients’ or ‘Standard Clients’. They see the same generic storefront products, quote forms, payment gateways etc.
If, when a user logs in, you want them to see something completely different to the Storefront, then you can make them a ‘Custom Account’.
How do you do this?
Firstly you need to be on the Enterprise Pro plan.
Then, once a client is created, you can edit that clients settings. Click on the Settings button on the Client page. In here you can customise this client account. You can add products, approval systems, budgets and so on. All of these changes can be made while the user still logs in at the storefront. However, if you want to customise the login process for a client, you can in fact ask them to login at a separate, unique web address. CLick on the URL setting on the Settings menu. You can also give them a special domain name.
There is no limit to the number of ‘Custom Clients’ (or ‘Custom Account’) that you can have. In fact all your clients could be customised in some way. If that was the case, the Storefront Settings would be literally, just the default settings for new accounts, until you customise those too.