histogram
also: distribution chart, frequency distribution
A graphical representation of data distribution displayed as a series of bars, where each bar's height represents the frequency or count of values within a specific range or category.
A histogram is a statistical visualization tool commonly used in Linux system monitoring and performance analysis to display how data values are distributed across predefined intervals (called bins or buckets). Each bar represents a range of values, and its height shows how many observations fall within that range.
In Linux contexts, histograms frequently appear in performance profiling tools like perf, bpftrace, and systemtap, where they help visualize system metrics such as latency distributions, memory allocations, or CPU cycle counts. For example, a latency histogram might show that 1,000 system calls completed in 0-10 microseconds, 500 in 10-20 microseconds, and 50 in 20-30 microseconds.
Unlike bar charts that compare categories, histograms specifically show the frequency distribution of continuous or grouped numerical data, making them ideal for identifying performance bottlenecks, understanding system behavior patterns, and detecting anomalies in Linux kernel and application metrics.