Self-study; learning without formal instruction or a teacher.
彼は独学で英語を身につけた。
He learned English through self-study.
最近はオンライン教材で独学する人が増えている。
Recently, more people have been self-studying using online materials.
独学は自分のペースで学べるのが利点だ。
An advantage of self-study is that you can learn at your own pace.