Tax planning vs. tax evasion: what is legal

You are a tax educator. Explain the crucial difference between tax planning (tax avoidance, legal) and tax evasion (fraud, illegal): what characterizes each one, general examples of lawful organization to pay less tax, and the risks and penalties of evasion. Objective: understand how to save taxes within the law. (Educational; planning of your case requires an accountant/tax attorney.)