Cricket tables are ranked on points. In limited-overs cricket (T20, 40- or 50-over games) the common system is 2 points for a win, 1 each for a tie or a no result, and 0 for a loss. A no result (NR) is a game that could not be finished, usually because of weather. Draws only happen in timed or multi-day games, which some club leagues still play and score on their own system.
The tiebreaker is net run rate (NRR): the runs a team scores per over, minus the runs it concedes per over, across the whole competition. A team scoring 8.0 an over and conceding 7.5 has an NRR of +0.500. Under the usual playing conditions, a team that is bowled out is counted as having faced its full quota of overs, so being dismissed early costs you.
The one thing that trips everyone up is overs notation. 16.2 overs means 16 overs and 2 balls — 16⅓ overs, or 16.333 — not 16.2. Get that wrong and every NRR in the table is slightly off.