As far as I know it's the same thing except:
- You will automatically subscribe to new cards added to the board.
- You won't see the eye symbol on every card if you're subscribed to the board.
From this card on the trello development board:
Board and List Subscribe
People are looking for a way to get notified of all actions on a given
card, list, or board, without being assigned to it. Subscribing will
do that.
You can also subscribe to a list from the list menu (upper right
button). You'll get notified of all actions that happens to cards in
that list. The list will show a subscribe icon, but cards in that list
won't show the icon unless you've subscribed to them.
You can subscribe to a board from the board menu. It will add a
subscribe icon to the board title. Like lists, it's not going to add
an icon to every single card on the board.
Permissions: You won't be able to subscribe to something unless it's
on a board you can see. If you switch a board from public to private,
people subscribed to it won't get notifications and it won't show up
in your subscriptions list.
And here's from the trello blog introducing this feature:
Subscribing to a card lets you get notifications as if you were added
to it. When we launched it back in May, people loved it. The biggest
feedback we received was that people wanted the ability to subscribe
to whole boards and individual lists. We admit we were a bit hesitant
— that’s a lot of notifications, at least for us. But there are some
cases where it makes sense. Sit back and imagine…
Let’s say you are on a Trello board shared by two other roommates.
It’s filled with household tasks, upcoming bills and rent, grocery
needs, etc. There’s not much activity so you want to know about
everything that’s going on. Subscribing to every card would be a…
chore, so you subscribe to the whole board. But you find that you
don’t really need to know that Steve finished washing the dishes. You
really only need to know about what to do next, so you just subscribe
to the “New” list. Next thing you know, you’re out grocery shopping
and hey look, you get a push notification on your iPhone or Android
device. ”Get butter” was added to the list. You pick up a dozen boxes
and return home where everyone thanks you profusely.
Anyway, you get the idea. (Also you might want to cut back on the
butter…)
We’re excited to announce the launch of board and list subscribe. We
can’t guarantee that it will make you the hero of your household, but
we hope you find it useful. How does it work? To subscribe to a board,
just click the “Options” button, then select “Subscribe”. To subscribe
to a list, click the menu button in the list header, and select
“Subscribe”. Now you can sit back and see changes without having to
click through to every board.
