Agenda cards represent the data associated with one of our goals. To score an agenda, we must advance it by the number of counters indicated by its difficulty rating, which is the number in the symbol in the card's upper right corner. The only cards that can be advanced are agendas, and those nodes that indicate they can be advanced. We can only advance agendas and appropriate nodes after they have been installed. To advance a card, we take an action to pay from our bit pool and place an advancement counter on the card. agendas cannot be advanced further after they are scored, but nodes can be advanced before and after they are rezzed.
If we score an agenda card, we remove the card from the data fort, set it aside and clear it of advancement counters, score its agenda points (the number in the symbol in the lower right corner of the card), and receive whatever bonus it gives, as indicated in its text box. agenda points exist independently of agenda cards, and we may choose to represent them with counters, since we may sometimes pay them out to fulfill card conditions, or increase them through special card effects. The bonus we receive for scoring an agenda is active as soon as applicable.
Scoring an agenda does not require an action, but we can do it only at the start of our turn or after any of our actions. We can, however, choose to put off scoring an agenda that has been advanced to its difficulty rating (certain card effects may make this desirable).
Your goal is to liberate agendas from the data fort(s) they're hidden in. If you access an agenda card, then you've liberated its data. You remove the card's advancement counters and set the card aside, and you score the number of agenda points stated on it, though you don't get the bonus described in its text. You may want to keep track of agenda points with counters: they exist apart from agenda cards, and card effects may increase them, or strip them away.
In this diagram, the agenda card shown is the agenda card being advanced in the data fort shown. If two more advancement counters are placed on it, the agenda card can be removed from play; we then score 1 agenda point, and the bonus of an extra action each turn. If the Runner liberates this agenda, he or she simply scores 1 agenda point.