A Change of Status occurs when an alien enters the United States legally on a non-immigrant visa and seeks to change to a different non-immigrant visa classification without having to leave the country. When a temporary work visa petition (for example: H-1B) is filed and approved as a change of status, the foreign national will automatically be in that status.
When filing a Change of Status petition, the applicant can not travel outside the U.S. while the petition is pending with USCIS. If international travel occurs before the approval of the petition, USCIS will change the petition to be processed via consular processing in the individual’s home country.
A person wishing to come to the United States completes the application interview in a U.S. embassy or consulate in his or her home country.
While a change of status automatically occurs upon petition approval, under consular processing the applicant is required to apply for a visa at a U.S. embassy or consulate in his or her home country to re-enter the U.S. in the corresponding status.
Depending on the country you are from and where you live in the United States, your local US consulate may process visa applications faster than your local USCIS office. You may check the current processing times on the USCIS website, then compare them with the times provided by the US consulate in your country.
If you are legally staying in the U.S. and have no plan to travel internationally while the petition is pending with USCIS, normally you should choose Change of Status. If you currently live outside U.S. or is in the U.S. in a status, such as on a B-1 visa, which expires before the petitioned status would start, you need to choose Consular Processing. Or If you need to enter the United States quickly, a quicker consular processing time may be a reason to pick this option.