At its core, ArtStation is a website builder connected together in a social network for discoverability. This was the original vision of ArtStation right from the beginning.
A user has 2 places where your portfolio will show:
Your community profile is where people involved in the ArtStation community discover you. There are many avenues for discovery, for example: appearing on searches, the activity feed, the Walls of art, through recommending/suggestions.
The community profile and community portfolio is social by nature. Users can Follow you. Users can Like your work. Users can comment on your work. Users can message you. Users are also able to see suggested/recommended works by other artists similar to you for discoverability.
Generally, the community profile is good for discoverability within the community. That is its primary purpose.
Every artist on ArtStation is given a free portfolio website to showcase your work (and only your work) to recruiters and clients without the distraction of the community and the potential for your client clicking to other artists.
Your ArtStation-powered website is very different from the community profile. It's not social: Users cannot Follow you. Users cannot Like or Comment on your work.
Your website can be customized. In the free version of ArtStation, you can add a few pages and customize the menu. On the Pro version, you can use a variety of themes with many more options to customize. You can even add your own domain name so that the ArtStation branding is removed entirely and it doesn't look anything like ArtStation at all.