Check out example codes for "ng g". It will help you in understanding the concepts better.

Code Example 1

The name of the TypeScript configuration file for tests. Default: ... --skipTests=true|false. When true, does not create "spec.ts" test files for the app. Default: false

While generating component using cmd
>ng g c component-name --skipTests

Code Example 2

ng g directive <name> [options]

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