TSConfig

A series of entries which re-map imports to lookup locations relative to the baseUrl if set, or to the tsconfig file itself otherwise. There is a larger coverage of paths in the moduleResolution reference page.

paths lets you declare how TypeScript should resolve an import in your require/imports.

{
  "compilerOptions": {
    "paths": {
      "jquery": ["./vendor/jquery/dist/jquery"]
    }
  }
}

This would allow you to be able to write import "jquery", and get all of the correct typing locally.

{
  "compilerOptions": {
    "paths": {
        "app/*": ["./src/app/*"],
        "config/*": ["./src/app/_config/*"],
        "environment/*": ["./src/environments/*"],
        "shared/*": ["./src/app/_shared/*"],
        "helpers/*": ["./src/helpers/*"],
        "tests/*": ["./src/tests/*"]
    },
}

In this case, you can tell the TypeScript file resolver to support a number of custom prefixes to find code.

Note that this feature does not change how import paths are emitted by tsc, so paths should only be used to inform TypeScript that another tool has this mapping and will use it at runtime or when bundling.