The ISO 19124 series is focused on calibration and validation (Cal/Val) of remote sensing data, which are collected by a sensor on-board a platform in a mission, and products derived in part or whole from the data. The ISO 19124 series defines the metadata related to the calibration and validation process that has not been defined in other ISO/TC 211 International Standards. The metadata allows the data providers to provide a standardized description of the Cal/Val process they have applied to the data. It allows the data users to get the same forms of metadata from different data providers. This document addresses the overall framework and common calibration and validation processes related to Earth observation data and derived products from different types of remote sensors. Subsequent parts in the ISO 19124 series will target data from specific sensors, for example, infrared, ultraviolet/visible/near-infrared, microwave, or broadband, products derived from those data, and calibration and validation sites. Calibration addresses a geometric, radiometric, or spectral correction of the data. Validation addresses an evaluation of the quality and the accuracy of the data and the derived products.