Every time a player does an action that is specific to hunger, health, or moves, the configuration file updates certain information. It also updates when a player signs on and signs off.
Ocelot is a plugin mainly to show real-time updates of players in the game to people on a server's website. Ocelot does not, however, create a page itself on a servers website. The server-owner has to load the information from the configuration file onto the website with their own code. Ocelot is, essentially, a sort of middleman software/plugin.
The config.yml file, which is generated by the plugin, would generally look something like this:
player1:
online: false
location:
x: -323
y: 65
z: 203
foodlevel: 20
health: 20
player2:
online: true
location:
x: 3232
y: 66
z: 23
foodlevel: 16
health: 12
player3:
online: true
location:
x: -9992
y: 68
z: 21
foodlevel: 0
health: 3
To view a real-time example you can view ocelot.in and scroll to the bottom section that says Players Online. If there are no players online currently then it will not show any players.
The way each website looks will be different and the code to update in real-time might not be used on some instances of Ocelot depending on how a servers website is set up.
Here's an example of what it looks like on ocelot.in:
