What the gate actually gates
The password sits on the page, in front of everything else. Someone with the URL who does not have the word faces the prompt: the session exists, but the agenda, the speaker details and the sign-up form stay behind it. That matters more than it sounds, because a page you would rather keep to guests still carries information the wider world might read โ who is speaking, what is promised, who is expected.
It also changes who can register. On an open page anyone curious can leave a name; on a gated page the form only appears once the word is typed. The gate is not a bouncer checking identities, and nothing here verifies that a person is who they say they are. It is a shared secret, which is a simpler and more honest mechanism: whoever holds the word can open the form, and whoever you told holds the word.