serijos

Serijos is the Lithuanian term for “series” and is used to describe a collection of items linked by order, progression, or a shared theme. The word appears in everyday language to refer to sequences, installments, or consecutive parts in various fields. In many languages, the cognate term series also covers mathematical, literary, and media contexts, sometimes with subtle distinctions between a sequence, its sum, or its grouped parts.

In mathematics, a series is the sum of the terms of a sequence. A finite series has a definite sum; an infinite series may converge to a limit or diverge. Partial sums—the sums of the first n terms—are used to study convergence. Common types include arithmetic series, where successive terms differ by a constant, and geometric series, where each term is a constant ratio of the previous one. Convergence tests such as the ratio test, comparison test, and the alternating series test help determine whether a series converges and to what value. Notable examples include the geometric series sum 1/(1−r) for |r|<1 and various series used to represent functions, such as Fourier and power series.

In media and publishing, serijos refer to sequences of works released over time: TV series and web series consist of episodes that advance a narrative across seasons; book series group novels sharing characters, settings, or themes and are read in a particular order. The term also appears in broader cultural contexts to denote any ordered sequence of related items or events.

See also: Series (disambiguation).