Data is the Latin plural of datum, "a thing given," the neuter past participle of dare, "to give." English took it in the 1640s, and its first use was strictly mathematical: a fact given as the basis for calculation in a problem — the things granted at the start so the reasoning can proceed.
It belongs to the small set of Latin nouns English borrowed with their inflections intact, alongside alumnus and alumni, criterion and criteria, index and indices. But data has travelled furthest from that grammar. Most English speakers now treat it as a mass noun taking a singular verb, and datum has all but vanished. The modern senses are recent: numerical facts collected for reference from 1897, and information stored and transmitted by computers only from 1946.
data (n.) 1640s, "a fact given or granted," classical plural of datum , from Latin datum "(thing) given," neuter past participle of dare "to give" (from PIE root *do- "to give"). In classical use originally "a fact given as the basis for calculation in mathematical problems." From 1897 as "numerical facts collected for future reference." The meaning "transmittable and storable information by which computer operations are performed" is recorded by 1946. Data-processing is from 1954; data-base (also database ) "structured collection of data in a computer" is by 1962; data-entry is by 1969. also from 1640s