The Los Angeles Unified School District's Magnet Program is a court-ordered voluntary integration program that is available to students in grades K through 12 who live within the LAUSD boundaries. What that means in more simplistic terms is that years ago, there was a lawsuit alleging that LAUSD discriminated against minorities and provided fewer educational opportunities to them. As a result of that lawsuit, the Magnet Program was instituted to ensure that resources are extended to minority students as well.
There are over 150 schools that offer the Magnet Program. Each magnet school has a different theme, and offers a curriculum that incorporates and focuses on that theme. There are magnet schools available at each grade level, though I believe there are only two magnet schools that are open to kindergarteners.
With the exception of gifted/high-ability magnets, magnet schools are open to all LAUSD students and admission is determined through a points and lottery system. Gifted/high ability magnets admit only qualified students, but the admissions process for those who qualify is also through the points and lottery system.