The title tag is the HTML element that specifies the title of the webpage. The title tag is displayed at the top of your browser, in the search results, as well as in the bookmarks bar.
The meta description is an HTML tag that provides a short and accurate summary of the webpage. The meta description is used by search engines to identify a webpage's topic and provide relevant search results.
The h tags represents the headings of the webpage. The h1 tag is the most important h tag, and describes the main topic of the page, while the rest of the tags describe the sub-topics of the webpage.
The alt attribute specifies an alternate text for an image, if the image cannot be displayed. The alt attribute is also useful for search engines to identify the subject of the image, and helps screen readers describe the image.
The lang attribute declares the webpage's language, helping search engines identify the language in which the content is written, and browsers to offer translation suggestions.
The favicon is the icon that is being displayed in the browser's tab, when the webpage is being bookmarked, and sometimes even in search engine results.
The images format represents the images that are not served in a next-generation file format. Images served in a next-generation format improve the webpage's load performance.
The defer attribute allows the browser to download the scripts in parallel and execute them after the webpage has been parsed, improving the webpage's load performance.
The structured data tags help the search engines better understand the content of the webpage, and allows them to create rich snippets in search results.
The style attribute contains CSS style rules that are applied to the element. Inline CSS code unnecessarily increases the webpage's size, and can be moved in an external CSS file.