Cub Scouting, Scouts BSA, and Venturing are programs of Scouting America — so in that sense, Cub Scouts, Scouts BSA members, and Venturers are all members of the same organization.
However, they are entirely different programs: Cub Scouting is a family-oriented program designed specifically to address the needs of younger boys and girls. Scouts BSA is designed to achieve the aims of Scouting through a vigorous outdoor program and peer group leadership with the counsel of an adult Scoutmaster.
Venturing provides positive experiences through exciting and meaningful youth-run activities that help members pursue their special interests, grow by teaching others, and develop leadership skills.