Business logic and what violates it?

Question

Software testing

The severity of bugs is determined by the following gradation:
S1 Blocking (Blocker)
A blocking error that brings the application into a non-working state, as a result of which further work with the system under test or its key functions becomes impossible. Solving the problem is necessary for the further functioning of the system;
S2 Critical
A critical error, a key business logic not working correctly, a security hole, a problem that temporarily crashes the server or renders some part of the system inoperable, with no way to resolve the problem using other entry points. Solving the problem is necessary for further work with the key functions of the system under test;
S3 Major
Significant bug, part of the main business logic does not work correctly. The error is not critical, or it is possible to work with the function under test using other entry points;
S4 Minor
A minor error that does not violate the business logic of the part of the application under test, an obvious user interface problem;
S5 Trivial
A trivial bug that does not affect the business logic of the application, a poorly reproducible problem that is hardly noticeable by means of the user interface, a problem of third-party libraries or services, a problem that does not have any impact on the overall quality of the product.
Explain what business logic is (although it seems intuitive, but you need to make sure) and what violates it.
For example: Edit mail considers [email protected] as invalid, but considers [email protected] correct.

Answer 1

When a business orders a software product, it has certain goals in mind.
When a coder writes a product, he creates a script to meet these goals (logic).
From this we get:
Business logic - a script that performs business goals.