How to access values of Checkbox, Radio and Multiselect fields through scripting?

How to access values of Checkbox, Radio and Multiselect fields through scripting?

As I understand Checkbox field values, for example, are stored in a different way. How can I access them through scripting? Is there a detailed description of this somewhere in the documentation?

If I have Checkbox field 1 with:
- Option 1
- Option 2
- Option 3

What is the code to read if for a particular record Option 1 is on or off?