• Data reference period
• Place of residence (Portugal)
• Age group

• RESIDENT POPULATION:  The persons who regardless of the fact that at the moment of observation ' 0:00 a.m. of the reference day ' are present or absent in a given housing unit, this unit being where they live during most of the year with their family, or where they have all or most of their belongings.
• REFERENCE PERIOD:  Period to which the information refers and which may be a specific day or a time interval (month, fiscal year, calendar year, among others).
• AGE GROUP:  The age interval in years to which a person belongs at the time of reference.
• PERSONAL COMPUTER:  Personal use system with own processing and communication capabilities: Desktop and Tower ' geared to run general use applications; Workstations ' geared to process applications with significant processing and graphical demands; Laptops ' geared to run general use applications, characterised by its reduced dimensions and weight, with an autonomous electrical feed; Terminals ' input/output units without own processing capabilities, via which a user communicates with the computer.

(Persons aged between 16 and 74 years old using computer in the 12 months prior to the interview / Residente Population aged between 16 and 74 years old)*100