What does opt stand for?

For International students studying in the USA on an F1 visa basis, the USCIS provides them with two options:

Either after completion of their degree program (academic period), they leave the USA and return to their home country OR they choose OPT Jobs (which stands for Optional Practical Training)

A training program for students through which F1 students can gain on-the-job experience by applying for a job offer in their respective fields of expertise, generally for a period of 12 months (with a STEM extension period of 24 months).