Headtail

Headtail is a compound term that does not denote a single, universally recognized concept. In general usage, it describes the two ends of a sequence, object, or system—the head (beginning) and the tail (end).

In computing, head and tail are common commands that display the first and last parts of a text stream or file, and tools or scripts called headtail may combine these capabilities to show both ends of an input.

In data analysis and statistics, the head and tail describe a dataset or distribution's leading portion and trailing portion, or the extremes in a ranked list; analysts sometimes study the head and tail separately to understand structure or outliers.

In biology, head and tail denote the anterior and posterior ends of organisms or body segments; discussions of polarity or orientation in worms, insects, and other taxa may use head-tail descriptors, including informal uses of head-tail to reference polarity.

Other uses include brand names, project titles, or fictional concepts that adopt the term headtail. Because it is not a fixed technical term, interpretation depends on domain and context.