Photogrammetry is the science of obtaining information about physical objects through photographs, without needing direct contact. It involves measuring and analyzing captured images. The name comes from Greek roots meaning "light", "drawing", and "to measure". Key developments included using photography for mapmaking in the 1840s-1850s, the photogrammetric stereoplotter in the 1890s, and aerial photography from balloons and planes in the 1860s-1900s, advancing the field into the digital era.