Time-series graphs - GCSE Maths Definition

A time-series graph is a general term referring to any graph that shows data changing over time. On such graphs, the horizontal (x) axis represents time, and will usually be called t (rather than x). The vertical (y-) axis will represent the data being analysed; common examples include temperature, population and company sales/profits.

Time-series graphs can help visualise how data is changing with time, and can indicate any trends in the data, for which decisions may need to be made (e.g. turn the temperature down (if possible!), limit population growth to avoid overcrowding, increase advertising to (hopefully) increase sales).