You are right about network activated.
About the other two:
The user will always see all the plugins in their blog admin’s plugin list.
Activating a plugin means activating it only on the current blog, and you can deactivate it if it was previously enabled. These two options does not affect the other blogs in the network, only the current one.
More details here: http://premium.wpmudev.org/wpmu-and-buddypress-plugins/activating-and-deactivating-regular-plugins/