There are, generally speaking, 2 different kinds of warrants, arrest warrants and bench warrants.
Arrest warrants are much more serious and might result in you doing some real time behind bars. Police are much more likely to actively work an arrest warrant by visiting your home, homes of family members and known associates and your workplace. With an arrest warrant you should assume you are being actively sought by law enforcement.
Bench warrants are also serious but less likely to result in tracking you down to throw in jail. Bench warrants are issued for many reasons however the most common are a failure to pay a court fee, traffic ticket or parking citation. While law enforcement is required to notify you that a bench warrant has been issued they often send notice to the address associated with the ticket at that time. If you move it can be much harder to know that a bench warrant was issued. Bench warrants can turn a simple traffic stop into a ride to jail.
If a warrant is issued and you are caught by police (as opposed to turning yourself in) you may have a much harder time in getting charges dismissed, reduced or favorable sentencing. It’s important that you immediately contact an aggressive, common-sense criminal defense attorney to make sure as many options and rights are preserved from the very beginning.