Hi,
HikaMarket front-end allow you to manage your store directly from the front-end.
HikaMarket multivendor use the same front-end interface but it adds multivendor features.
As you can see in the compare page, the "front-end" version has a restriction on the number of vendors : 1
www.hikashop.com/extensions/compare-versions.html#user
It means that HikaMarket front-end just allow one single vendor, which is your vendor, your store, yourself.
You can set several users in your vendor account, with different right access etc, but the multivendor features are not in this version.
For the moment we don't have a "frontend to multivendor" product like we have for HikaShop (essential to business).
If you want to upgrade to the multivendor edition, please use our contact form and we will see to make you a manual upgrade with a virtual product.
Regards,