A small data file describing how a particular device or colour space reproduces colour, so software can convert colours between devices.
Defined by the International Color Consortium. A profile maps device values to a device-independent profile connection space (CIELAB or XYZ, D50), and conversions go device → connection space → device.
Embedding a profile does not change the colours; it labels what the numbers mean. Stripping it leaves software to guess.
A print shop's profile for coated stock tells design software which colours that press can reach.
Colour management across cameras, screens and printers depends on profiles being present and correct.