What's the difference between NIW self petition and employer petition?

I did self petition but I heard that the employer could also petition. What's the difference? Luckily my 140 was approved, but would it have been better if I asked my employer to sponsor?

to leah.welch558:

It would be better because your employer will pay all the fee and your employer's lawyer will prepare all the materials for you. But the downside is you will stuck with you until 180 days after your file I-485. So make sure you will stay with your employer for the next two years.