A ten-day residential course in silent meditation, free to attend.
Vipassana is a form of insight meditation. This page is about the courses taught "as taught by S.N. Goenka" in the tradition of Sayagyi U Ba Khin, run at centres around the world, including in India.
You learn one technique over ten days, living at the centre and keeping silence. The course is in fact twelve days long once you count the arrival and departure days. Teachers and organisers are volunteers.
According to the organisers, courses are run only on a donation basis. They are free to attend. Only people who have completed at least one ten-day course may give a donation, and first-time students may do so at the end.
Ten days is a long time, and the days are demanding. You live by the centre's rules, and you commit to the whole course. Please read the organisers' own description and code of discipline before you apply.
An intensive silent course is not for everyone. If you have ever had serious difficulty with your mental health, speak to the organisers and to your doctor before applying.
Go to dhamma.org, find a centre and the dates, and read what they say. Ask someone who has done a course if you can.