A boxplot is a method for graphically depicting groups of numerical data through their quartiles.Box plots may also have lines extending from the boxes (whiskers) indicating variability outside the upper and lower quartiles, hence the terms box-and-whisker plot and box-and-whisker diagram. Outliers may be plotted as individual points.
A histogram is an approximate representation of the distribution of numerical or categorical data. It was first introduced by Karl Pearson. To construct a histogram, the first step is to "bin" (or "bucket") the range of values—that is, divide the entire range of values into a series of intervals—and then count how many values fall into each interval.
A statistical process control (SPC) chart is a very useful tool for maintaining the quality of an ongoing, repetitive process. There are several different types of SPC charts, but the most common is normally referred to simply as a control chart. A control chart plots the ongoing performance of a process against expected outcomes based on statistics; these being the process average and multiples of the process standard deviation. The control chart allows a quick visual analysis of trends in the process and can readily show when results are outside expected limits.