Let us start with logistic regression. Recall that a logistic regression divides 2 sets by a line (or a hyperplane if we have higher dimensions)
The logistic regression yields values form 0 to 1, and we can consider the process as making an evaluation. In the process we get data and we calculate our evaluation by a formula.
For example we may have the following assignment: to compute if we have enough goods in storage to last for a week of sales. This is quite a common problem, and say some clerks report their numbers to their manager to figure it out. The manager collects information, processes it and makes an evaluation.
Note that this is how a logistic regression functions.