Online or on-line [on-láin] is an anglicism derived from the use of the Internet , with "em linha" being a literal translation of on-line, which is not commonly used in Portuguese.

In French, one says en ligne and hors-ligne; en línea is quite commonly used, especially in Europe, while online and on-line are more frequent in Latin American Spanish due to the strong influence of English and Anglicisms.

"Being online" or "being on the line" means "being available live." In the context of a website , it means being available for immediate access to a page in real time. In instant communication, it means being ready for the immediate transmission of data , whether spoken or written.

Online information system

In the context of another information , it means being fully operational, according to the functions performed in that network or system. Conversely, being offline represents the unavailability of user to the network or communications system.

In Portuguese, there is also the expression "fora de linha," which is used much less frequently.

For works such as books, the term "online version" refers to the internet version, as opposed to the printed version, the electronic version, or the CD version, and the printed version. Wikipedia only exists online.

Some dictionaries are sold today in print with a CD. The VOLP (Vocabulário Ortográfico da Língua Portuguesa) exists in both print and online versions. This term was adopted by internet users and became popular with the expansion of data flow through the internet, which began in the 1990s.

In Portuguese, the literal translation of the English term – “na linha” – is also used metonymically to mean being connected to a network or communications system. The terms also have the clearer meaning of “live,” “connected,” or “on.”