Both terms – hack and bug notify about an issue on the web site. But we are going to explain shortly the difference between the two.
Hack
This term is used to indicate and outside interference from a hacker. The hack could be to change the content or the way your site works without your knowledge, permission or interference.
Bug
The term is used to indicate that there is an irregularity with the site resulting from it’s improper development by the web programmers. Or there is an irregularity due to the update of the version of programming language or the platform used to build the site.
Examples:
Hack is when someone successfully cracks the password for the administrative panel of your web site through specialised software. (Read more on What is brute force attack and how to protect ourselves). Even if the hacker doesn’t make any changes, it is still considered hacking.
Bug is when you have a web site or web application with some functionality that requires a special software. And this software stops being supported by the company or by the operating system/browser, on which your site/application is being used. An example of this were all the web sites that used the Flash technology. Mac iOS stopped the support of Flash technology on their devices and all those web sites couldn’t function properly because of it.
Bug is when the programmer didn’t make the “Send” button large enough and the text in the mobile version extends outside the button. Hack is when someone accesses the files of your web site and instead of “Send” writes “Mind your business” on your contact form button.