The "position" property in CSS is used to control the positioning of an HTML element on a webpage. It has values like static, relative, absolute, fixed, and sticky. By using the "position" property, you can create interesting layout effects on your webpage.

The "hover" property in CSS is used to specify the styles that should be applied to an element when a user hovers their mouse over it.

The <hr> tag in HTML is used to insert a horizontal line on a webpage, typically to visually separate content or create a visual divider between sections.

The <section> tag in HTML is used to define a section of content within an HTML document. The <section> tag is a semantic HTML tag that helps to structure the content of a webpage, making it more accessible and easier to understand for both humans and search engines.

The <button> tag in HTML is used to create a clickable button on a webpage. Buttons are a common element of web design, and can be used for a variety of purposes, such as submitting forms, triggering actions, or navigating to different pages.