An introductory fellowship (sometimes called introductory program, seminar program, or scholars program) is a program in which a dedicated group meets several times to learn about effective altruism. Typically, introductory fellowships consist of weekly readings and discussion groups for a period of 6–10 weeks, in groups of 3–10 people. Fellowships are a high-intensity and high-fidelity way of learning about effective altruism, and many local effective altruism groups run an intro fellowship as an early/middle part of their funnel.
You can learn more about intro fellowships here. If you're interested in running your own intro fellowship, see this post.
EA Virtual Programs runs regular intro fellowships; anyone can apply to participate.