Albedo in latin means the extent of whiteness. In planetary terms, this indicates the extent to which the sun light and other particles are scattered in different angles from the surface of the planetary body in comparison to the total radiation received by the planetary body. Usually it is measured from 0 to 1 i.e. a perfect black body which absorbs all incident radiation to a purely reflective body that reflects almost all of the incident radiation. In case if the specific wavelength is not provided, then it is to be assumed that, the albedo value represents the entire spectrum of the incident solar radiation.
Mathematically, surface albedo can be represented by the ratio of radiosity to the irradiance received by the surface. The diffuse reflection varies based on surface and atmospheric composition of the planet, the location of planet in accordance with that of the sun and time.
To analyse the martian surface and atmospheric components, it is important to have the martian surface albedo. With this objective in mind and to provide adequate data for future Mars missions, ISRO has arrived at the global Short Wave Infra Red (SWIR) albedo map in the wavelength band of 1.64-1.66µm. The Mars Orbiter Mission (MOM) had facilitated this using the onboard Methane Sensor for Mars (MSM).
Albedo Map of Mars using MSM onboard Mars Orbiter Mission (MOM)
A bit more detailed explanation of the albedo data is provided in ISRO post here.
During the last decade, NASA had successfully derived the albedo map of mars using its MGS Thermal Emission Spectrometer (TES) in the visible and near-IR reflectance. More details can be found from the NASA Jet Propulsion Lab page.