See above
We host live demo versions of both products: WebLink, Web Access. Typically WebLink would be used to publish some of your repository content to the public, so it's common to not require authentication. Web Access would usually be set up to require authentication (unlike our demo).
Weblink is read-only and can have a user setup for public access. Web Access gives your the same features as a user accessing the Laserfiche client.
As Brain and Blake mentioned above, Web Link is the public portal through which you can share the content of Laserfiche repository to general public. See the attached example of City of Mountain view, CA.
Web Access is the authenticated web version of Laserfiche Client with the exact same features of Desktop version of Laserfiche Cleint.