Ok, here goes....
There are two types of International cricket games - Test matches and One Day matches.
One Day matches were invented in th 70s for Television. Each team gets to bat for a maximum of 50 overs (an over is 6 balls plus any for "foul" balls), and whoever has the better score wins - a tie occurs if both end with the same number of runs.
A good score varies with the quality of the pitch (the area on which the bowler bowls), but generally a score by the first team batting of between 200 and 300 is reasonable. Anything over 300 is very good - unless it's a low quality pitch that makes it too easy for the batters.
The second team simply has to pass the first teams score.
A test match last up to five days. Each team can bat twice. A draw occurs if time runs out before both teams get to complete their alotted innings, without one winning.
Let's imagine an example. Team A bats and scores 350. Team B bats and scores 325 - 25 runs short of Team A, but not too bad. Team A bats again, scoring 250. Team B now needs to get past 275 to win.
If Team B is bowled out (all 10 wickets taken by Team A, less for any injured players who cannot bat) for less than 275 then Team A wins.
If Team B scores more than 275 they win.
If Team B scores exactly 275 then it is a tie (very rare - this requires either they all get out on exactly 275, or the time runs out with them on this score).
If Team B has not scored 275, but is not out when time runs out, then the game is a draw.
Draws are relatively common, but not so much as they used to be, it seems to me.
Now, in a test, timing is important. For both teams to bat twice in 5 days, they really only have 1.25 days per innings. So, the teams will usually keep that in mind.
But - one more confusion is the "follow on". If the team batting second is all out in their first innings, and are trailing the team who batted first by more than 200, then the first team can request that they bat again immediately - follow on.
So, if team A scores 500 runs, and Team B is out for example 287 then Team B may be asked to follow on.
Say then they get out for 260. - they now have a total of 547. Team A now only needs to get 48 runs to win.
So following on is a very good thing to aim for. With this in mind it is often that the first team will try to bat for longer than 1.25 days in their first innings.
As for batting defensively - well, unlike Baseball, in Cricket you can just hit a ball a small distance and not attempt a run. So, if your object is just to not get out, regardless of runs, then you can go defensive, attempting to just pass time. It's much harder to get someone out in these circumstances.
Why would a team go defensive? If they think it is impossible to win, but they can get a draw, then it's reasonable.
So, what's a good score in Test Cricket? Well, for the team batting first, usually about 450+ is good, IMO.
There, I think that's enough for now...
Duncan