In angular-cli.json at outDir key you can define your build directory;
these are equivalent
ng build --target=production --environment=prod
ng build --prod --env=prod
ng build --prod
and so are these
ng build --target=development --environment=dev
ng build --dev --e=dev
ng build --dev
ng build
When building you can modify base tag () in your index.html with --base-href your-url option.
Sets base tag href to /myUrl/ in your index.html
ng build --base-href /myUrl/
ng build --bh /myUrl/