This really is a massively open-ended statement. There are a few aspects to the attitude that most take out.
First of all, you're out there to win. You don't want to waste the Tues/Thurs training, the pre-season, getting to the ground early, etc. on getting battered. You're prepared to do little niggly things that just might give your side an extra 1% advantage; like chatter, using bounce throws all day to soften the ball up, etc.
But with that, as soon as you leave the field, it's part and parcel of playing competitive sports that you engage with the opposition after the match, talk about the game and often you'll know a few blokes from the other team and have a chat about other stuff too. The guy who might have been in your ear all game giving you a bake is having a beer with you after the game. I think in the eyes of most, that's how it should be.
Another aspect to is that I think there is still a lot of reverance for the little aspects of cricket ettiquette; such as waiting for the umpires and fielding side to take the field before the batsmen do, not running if the ball has hit the batsman, etc.
But mainly, especially with cricket, you've got to go out there to have fun. You're spending 6 hours out of your weekend playing the bloody thing, you may as well enjoy it! Especially when you're in the field for 100 overs; often it's the banter that keeps you alive. I know most of the stuff I say in the field is usually just in-jokes with other guys in the team, making fun of each other. But at the same time, as soon as the bowler comes in, it's game on, and for the next 10 seconds after that, you might slip in a few jibes here and there.
I think there's a real "on/off" culture about cricket here. When it's game on, it's really game on. But doing that for so long isn't enjoyable by nature; you can't do it all day, nor can you do it when the game is over, so in a way you switch gears throughout play, training or anything cricket.