Span

Span is a general term for the extent between two endpoints, whether in space or time. It appears in many fields with related meanings, often centering on coverage, reach, or interval rather than a fixed size.

In mathematics and engineering, span can refer to concrete distances as well as abstract concepts. The distance between supports in a structure, such as the main span of a bridge, is a common engineering use. In linear algebra, the span of a set of vectors is the subspace consisting of all possible linear combinations of those vectors; it defines the space that the vectors generate.

In time, a time span is the interval between a starting moment and an ending moment. In everyday language, spans of time describe durations, such as a span of years or decades.

In computing and the web, the HTML span element is an inline container used to group inline content for styling or scripting without introducing block-level formatting. It has no inherent semantic meaning of its own and does not force line breaks, making it a flexible tool for text styling.

In related contexts, span can describe the reach or range of a system, the extent of a spectrum, or the width of a component in construction. Across disciplines, the core idea remains a measured extent from one boundary to another.