CSS Object-position is a CSS property that allows you to specify the exact position of an element within its parent container. It is especially useful for positioning background images, but can also be used to position other elements. Object-position can be used to precisely position elements relative to the top,
From Wikipedia
Cascading Style Sheets (CSS) is a style sheet language used for specifying the presentation and styling of a document written in a markup language, such as HTML or XML. CSS is a cornerstone technology of the World Wide Web, alongside HTML and JavaScript.