Your project folder contains a lot of files that were generated for you. To give you a good understanding of which files do what, we organized them by groups in this document. Also the relevant files for each topic are also mentioned in the other Guides.
config.xml # configuration of your Cordova project
platforms/ # platforms you installed
plugins/ # plugins you installed
www/ # will contain the build of your web app, before Cordova is added
bower.json # dependencies like Angular & Ionic installed to app/bower_components/
gulpfile.js # configuration of all the Gulp tasks
gulp/ # more Gulp tasks
package.json # dependencies like Gulp plugins installed to node_modules/
app/
└── index.html # single most important file, everything is wired together here
└── app.js # include modules YOU create, for now only 'main'
└── main/ # all other app files, angular files, styles, assets, ...
├── assets/ # assets: fonts, images, translation, etc... go here
├── constants/ # angular constants
├── controllers/ # angular controllers
├── directives/ # angular directives
├── filters/ # angular filters
├── services/ # angular services
├── styles/ # scss styles
├── templates/ # angular templates
└── main.js # routing, angular module dependencies
└── otherModle/ # possibly more modules
└── ...
.eslintrc # ESLint base configuration
.eslintignore # ESLint ignore configuration
test/
└── karma # karma unit test
└── protractor # protractor e2e tests
karma.conf.js # karma configuration
protractor.conf.js # protractor configuration
res/ # resources folder for splash screens and app icons
.bowerrc # bower configuration
.editorconfig # editor configuration
.gitattributes # git's attribute configuration
.gitignore # git's ignore configuration
.travis.yml # travis continuous integration configuration
.yo-rc.json # yeoman's .yo-rc.json
jenkins.sh # shell script for jenkins continuous integration
README.md # the generator's README.md