This is the 8947th most frequent Russian word.
рэб
"Рэб" is an abbreviation in Russian for "радиоэлектронная борьба" (radio-electronic warfare).
In this sentence, 'рэб' is used as an abbreviation, possibly denoting an educational or technological center.
Он посетил рэб, чтобы научиться компьютерным технологиям.
He attended the 'REB' to learn computer technology.
Here, 'рэб' refers to a specific program or resource aiding the person in understanding programming.
Этот рэб действительно помог мне лучше понять программирование.
This 'REB' really helped me better understand programming.
In this context, 'рэб' seems to denote a course or workshop hosted by the school.