Time Plot vs Scatterplot
Both terms below come up in the same part of the course, and students mix them up. Here is each one defined on its own, side by side, so you can see where they part company.
Time plot
Graphs and displays
A time plot graphs a quantitative variable against time on the horizontal axis, with the points usually connected in time order.
A time plot keeps the order of the observations, which is exactly the information a histogram of the same numbers throws away. You read it for trend, for repeating seasonal patterns, and for sudden jumps or breaks. For example, monthly rainfall of 2.1, 2.4, 3.0, and 3.6 inches from January to April rises at an average of inch per month. Shuffling those four points would destroy the trend while leaving the mean and standard deviation untouched.
Scatterplot
Graphs and displays
A scatterplot graphs paired values of two quantitative variables as points, showing the direction, form, and strength of their relationship.
A scatterplot plots each individual as a point, with the explanatory variable on the horizontal axis and the response variable on the vertical axis. You read it for direction (positive or negative), form (linear or curved), strength (tight or loose), and any outliers. For example, plotting hours studied against exam score for 30 students may show an upward, roughly linear cloud of points. When the pattern looks linear, a least-squares regression line can summarize it.