If you are an employee and you have completed your probation period and they fire you without a reason, you can sue them for wrongful termination and you might even get something out of it. Talk to the employment standards or talk to a lawyer to find out.
Normally the employer can lay you off because they don't have work or because you did something wrong although they have to tell you the reason. If you have 2 week notice, they can have you pack your stuff immediately and leave but they will have to pay you the two weeks anyway in that case. The reason they often prefer to lay people off that way in N-America is that they fear that employees who have been laid off and are working their notice are going to hold a grudge and may sabotage or steal from the employer.
A former employer of mine had to pay a settlement to a lady they fired. She had passed her probation period and gotten a good review but shortly after that they found that she was pitting employees against each other, going around and saying that so and so said this about you and back to the other guy causing a lot of bad feelings and arguments. They fired her and she got a lawyer and argued that she had a good review after her probation ended and she was never given any warning on record for bad conduct. They decided to settle with her rather than have her bring the case to court. I don't know how much she got in her settlement but I was told it was a 5 digit sum. The correct way to get rid of her would have been to give her a warning for bad conduct and put that in her file. They could have fired her if she kept it up.
