In the Meebhoomi portal of Andhra Pradesh, a Field Measurement Book (FMB) is a significant land record document containing details about land parcels. It includes information like survey numbers, ownership details, land area, boundaries, land use, surveyor information, and encumbrances. FMBs are essential for property transactions, land records management, and dispute resolution, providing accurate and up-to-date land information. Users can access and download FMBs from the Meebhoomi portal for various land-related activities.