HTML interview questions covering document structure, semantic HTML, headings, links, images, tables, forms and core markup fundamentals.
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HTML stands for HyperText Markup Language. It defines the structure and meaning of content on a web page. Browsers parse HTML elements to build the document structure that users see and assistive technologies can interpret.
HTML5 is the modern evolution of HTML used for structuring web documents and applications. The term is commonly associated with semantic elements, improved forms, native audio and video, canvas, and APIs introduced during the development of modern HTML.
The DOCTYPE tells the browser which document type and rendering mode should be used. The HTML5 declaration is simply <!DOCTYPE html>.
A basic HTML document contains a DOCTYPE followed by the html root element. The head contains document metadata and linked resources, while the body contains the page content presented to the user.
The head contains metadata and resources that describe or support the document, such as the title, character encoding, viewport configuration, stylesheet links, and selected metadata for search engines.
An HTML element is a component of the document, usually represented by a start tag, content, and an end tag. A tag is the markup syntax used to declare an element, such as <p> or </p>.
Historically, block-level elements normally start on a new line and occupy the available horizontal space, while inline elements participate within a line of text. Common examples are div and p for block-level behavior, and span and a for inline behavior.
Void elements cannot contain child content and do not have an end tag in HTML syntax. Examples include img, input, br, hr, meta, link, source, and area.
Semantic HTML uses elements whose names communicate the meaning and role of their content. Examples include header, nav, main, article, section, aside, footer, button, and form.
Semantic elements provide structural meaning that browsers and assistive technologies can expose to users. Proper headings, landmarks, lists, buttons, links, labels, and other native elements make interfaces easier to navigate and understand.
div and span are generic elements with no specific semantic meaning. A div is commonly used as a generic block container, while span is commonly used to wrap a small inline portion of content.
HTML provides h1 through h6 heading elements. They represent headings at different levels in the document hierarchy, with h1 representing the highest level and h6 the lowest.
strong indicates strong importance, seriousness, or urgency, while b draws attention without adding that importance. Similarly, em represents stress emphasis, while i represents text in an alternate voice or convention where italics are typically appropriate.
HTML provides unordered lists with ul, ordered lists with ol, and description lists with dl. li represents an item in an ordered or unordered list, while dt and dd represent terms and descriptions in a description list.
The anchor element creates a hyperlink, and its href attribute specifies the destination. The destination can be another page, a fragment within a page, an email or telephone URI, or another valid URL.
target controls where a linked resource is opened. For example, target="_blank" requests a new browsing context, commonly a new tab.
Use the img element with a src attribute for the image resource and an alt attribute for text alternatives. Meaningful images should have useful alternative text that communicates the relevant purpose or content.
The alt attribute provides a text alternative when an image cannot be perceived or loaded and is essential for many screen-reader users. The correct text depends on the image's purpose and surrounding context.
figure represents self-contained content that is referenced as a unit, such as an illustration, diagram, code listing, photograph, or chart. figcaption provides a caption or legend for that figure.
A table uses table as the container, tr for rows, th for header cells, and td for data cells. thead, tbody, and tfoot can group logical table sections, while caption provides an accessible table title or description.
colspan allows a table cell to span multiple columns, while rowspan allows it to span multiple rows. They are useful for representing legitimate grouped relationships in complex tabular data.
An HTML form groups controls used to collect and submit user input. The form element can specify where data is submitted with action and which HTTP method is used with method.
With method="get", successful form controls are encoded into the request URL query string. GET is appropriate for safe, repeatable operations such as search and filtering, and the resulting URL can often be bookmarked or shared.
A label gives an input control an accessible name and makes the form easier to understand and operate. When a label is correctly associated with a control, selecting the label can also focus or activate that control.
Common input types include text, email, password, number, tel, url, date, checkbox, radio, file, hidden, search, range, and color. The selected type communicates the intended kind of data to the browser.