If you wish to rank your website in search engines like Google then website or web application is the best choice. Ranking in Google means free advertising for sales etc. If you wish to provide offline content like games etc then app will be better. Please keep in mind that your website or web app can also act like an mobile app, for example How to add website to home screen of mobile
Which is cheaper mobile app or website – Talking about cost website or web app is cheaper than mobile app. Cost depends upon platform you use, features etc.
Website or application examples – Website is a piece of information where you can read content but cannot interact just like paper brochure. For example normal websites, blogs etc. Web application is a platform where you can interact like desktop version of Facebook, Youtube etc.
Website or app first – If you’re thinking about entering into internet world then I suggest website first because it is cheaper than mobile app, ranks in search engines. No one will download your mobile app unless you have strong brand image, no or few competition in your app category and spend huge budget on advertisements etc. You might also be thinking responsive website or mobile app responsive website is mobile friendly website and can act like a mobile app.
Difference between app and website –
Online – website can be used online only whereas mobile games etc can be use offline too.
Free advertising – after your website pages are ranked in the Google your website might get noticed (free advertising) if you’re ranked in first or second page. Mobile apps pages doesn’t get ranked in search engines. Website can be found anywhere in the web.
Space consumption – website or web application doesn’t consume space of your device where as mobile app needs to be installed so mobile app will occupy your device space which might make difference in performance.