The USNO-B catalog is an all-sky survey that presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for over 1 billion objects. The data were derived from 3.6 million separate observations of 7,435 Schmidt plates scanned by the Precision Measuring Machine (PMM) at the U.S. Naval Observatory Flagstaff Station. The catalog provides completeness down to \( V = 21 \), 0.2 arcsecond astrometric accuracy at J2000, 0.3 magnitude photometric accuracy in up to five colors, and 85% accuracy for distinguishing stars from non-stellar objects. The catalog is the result of a collaboration involving multiple observatories and institutions, and it is available for public access through various websites. The catalog's compilation involved several stages, including astrometric and photometric calibration, star/galaxy separation, and object classification. Despite its comprehensive nature, the catalog has limitations, such as systematic errors and the need for human verification due to its size. Future revisions aim to address these issues and improve the catalog's accuracy and reliability.The USNO-B catalog is an all-sky survey that presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for over 1 billion objects. The data were derived from 3.6 million separate observations of 7,435 Schmidt plates scanned by the Precision Measuring Machine (PMM) at the U.S. Naval Observatory Flagstaff Station. The catalog provides completeness down to \( V = 21 \), 0.2 arcsecond astrometric accuracy at J2000, 0.3 magnitude photometric accuracy in up to five colors, and 85% accuracy for distinguishing stars from non-stellar objects. The catalog is the result of a collaboration involving multiple observatories and institutions, and it is available for public access through various websites. The catalog's compilation involved several stages, including astrometric and photometric calibration, star/galaxy separation, and object classification. Despite its comprehensive nature, the catalog has limitations, such as systematic errors and the need for human verification due to its size. Future revisions aim to address these issues and improve the catalog's accuracy and reliability.