An M1 visa is a non-immigrant visa that allows foreign students to study in the United States at a vocational or non-academic institution:

Eligibility:
To be eligible for an M1 visa, you must:

Be accepted at an institution listed by the Student Exchange Visitor Program (SEVP)

Be proficient in English, as demonstrated by a standardized test like TOEFL or IELTS

Have enough funds to cover your stay in the US

Validity:
An M1 visa is usually valid for one year, but you can apply for an extension of up to three years

What you can study
You can study at an established vocational or non-academic institution, such as a post secondary vocational or business school. You can study subjects like cooking, language, flight school, cosmetology, or mechanical education.

What you can't do
You can't register for academic courses, seek employment, or work while on an M1 visa. You can only study part-time for up to six months, and you can only transfer schools within the first six months of your program.

What you can do after your program
You must leave the US within 30 days of the program end date on your Form I-20. You can participate in paid training (PT) after your program of study, but it must directly relate to your program. You earn one month of PT eligibility for every four months of program enrollment.

You can request an extension of stay from your DSO. You must provide proof of financial responsibility, and your DSO must confirm that you have an educational or medical justification for the extension.