Facebook is Providing autoposting functionality using website application and provides to display you website content on your facebook page.
But the Question how we can customise that post so it look right on page ?
Answer is Facebook Open Graph Tags.
Facebook open graph tags is nothing but a meta tags provided by facebook to read the data form your website at time posting the content on Facebook. If you Not include the meta tags then Facebook start read the html part of your link that will provided at time of posting your content programmatically.
Facebook Self defines this system on this URL
<meta property="og:url" content="http://www.nytimes.com/2015/02/19/arts/international/when-great-minds-dont-think-alike.html" /> <meta property="og:type" content="article" /> <meta property="og:title" content="When Great Minds Don’t Think Alike" /> <meta property="og:description" content="How much does culture influence creative thinking?" /> <meta property="og:image" content="http://static01.nyt.com/images/2015/02/19/arts/international/19iht-btnumbers19A/19iht-btnumbers19A-facebookJumbo-v2.jpg" />
These meta tags are defined on basis on your page content, put that meta tags in head tags of html page and facebook reads that page at time of feed posting on Facebook page.
And That it, you will get a proper post on Facebook.
For More info please visit this URL
Any suggestion or correction please mention in comment below Thanks.