Discrete data refers to categories or counts that can only be described in whole numbers; i.e. you can’t have half a defect or half a customer. This type of data is the opposite of continuous or variable data (temperature, weight, distance, etc.).
Typical discrete data refers to the number of defects, number passed vs. number failed as well as the counts of different categories; i.e. number blue, number red, number yellow, etc. Discrete data can be represented in percentages and ratios such as 2.1 guests per hotel room or a 75% occupancy rate, but the source unit, the guest, can still not be truly divided.