Tournament Stacks vs Small Bankrolls
There are many differences between tournament play and cash play when it comes to poker, even if the game is the same. A No Limit Texas Hold 'em tournament for example requires different strategy than a No Limit Texas Hold 'em cash game. The differences include not only your strategy but your approach, especially the way you approach managing your money.
After you pay your entry fee and you are buying in for a tournament, even if it is as little as a dollar, you start off with a large number of play chips, typically 800 or 1000. Everyone is starting with the same number and it is large enough, and the blinds are low enough to start, where you can spend a little on longshot hands and not be too concerned. You cannot, however, take the same approach in a cash game unless you're bringing quite a few dollars to the table.
If you have a small bankroll when you sit down to a cash game then you don't have very much leverage. You can't lose a few hands when you speculate and if it just happens to be your night for your luck to run bad before it runs good, you could end up broke before you get a first decent hand. This typically is more of the case in a limit game than in a no limit game. In a limit cash game there is a maximum bankroll each player can bring to the table, such as $10. While some players will come with less, this is closer to the way tournaments run as there is the potential that everyone will have about the same amount to begin with. In a no limit game someone could sit down with $100 while you may have only brought two dollars, which gives them a lot more longevity.
The important thing to keep in mind when trying different variations of poker games is that each one is different enough from the other that you can't play on autopilot -- you have to pay attention to what's going on at the table.