Difference between Shall and Should

Here are the differences between shall and should with examples:

Shall:

Shall expresses obligation or necessity, especially in legal or official contexts.
It often implies that some rule or law requires a certain action.
It is more formal and emphatic than should.

Examples:

The tenant shall vacate the premises by June 1.
Offenders shall be prosecuted to the fullest extent of the law.
Passengers shall remain seated until the aircraft comes to a complete stop.

Should:

Should expresses recommendation or expectation, not obligation.
It implies that something is advisable or appropriate, but not required.
It is less formal and emphatic than shall.

Examples:

You should eat a balanced diet to stay healthy.
Students should complete the assignment by Friday.
Drivers should yield to pedestrians in crosswalks.

In summary:

Shall expresses obligation or necessity, while should expresses recommendation or expectation.
Shall is more formal and emphatic, implying something is required or mandated. Should is less formal, implying something is advisable but not strictly required.
Shall is typically used in legal, official or formal contexts. Should is more commonly used in everyday speech and writing.

So in situations where something is actually mandatory or required, shall is appropriate. But where something is advised or recommended, though not strictly obligatory, should is more suitable.