A plot is the graphical representation of a mathematical function or a set of data. There are different types of plots, such as line plots, bar plots, or scatter plots.
Wikipedia uses the following definition of plot:
A plot is a graphical technique for representing a data set, usually as a graph showing the relationship between two or more variables. Graphs are a visual representation of the relationship between variables, very useful to quickly derive an understanding which would not come from lists of values.