• Data reference period
• Geographic localization (Members States of the European Union)

• REFERENCE PERIOD:  The length of time for which data are collected, e.g. a specific day, month or year.
• AGRICULTURAL HOLDING:  Technical-economic unit that uses common production factors such as labour, machinery, facilities, land, among others, fulfilling the following four conditions: 1) yield agricultural products or maintain, in good agricultural and environmental conditions, the lands that are no longer used for productive purposes; 2) reach or exceed a certain size (in area or number of animals); 3) be subject to a single management; 4) be located in a well-defined and identifiable area.
• UTILISED AGRICULTURAL AREA:  The area of the holding, which includes: arable land (cleared and under cover of scrub and forests), kitchen garden, land under permanent crops and permanent pasture.
• CABEÇA NORMAL ( CN ):  Medida pecuária que relaciona os efetivos, convertidos em cabeças normais, em função das espécies e das idades, através de uma tabela de conversão e, em que, um animal adulto da espécie bovina corresponde a 1 C.N.

Number of livestock units/ Utilized agricultural area