Difference between 'input' & 'button' tags

http://api.jquery.com/submit-selector/

Note that some browsers treat <button> element as type="submit" implicitly while others (such as Internet Explorer) do not. To ensure that markup works consistently across all browsers and guarantee that it is possible to consistently select buttons that will submit a form, always specify a typeproperty.

http://www.w3schools.com/tags/tag_button.asp

If you use the <button> element in an HTML form, different browsers may submit different values. Use <input> to create buttons in an HTML form.