HP 15″ Touch Laptop i5 8GB 512GB SSD with MS365

Fifteen or 15 may refer to:

• 15 (number), the natural number following 14 and preceding 16
• one of the years 15 BC, AD 15, 1915, 2015

A laptop computer or notebook computer, also known as a laptop or notebook, is a small, portable personal computer (PC). Laptops typically have a clamshell form factor with a flat-panel screen on the inside of the upper lid and an alphanumeric keyboard and pointing device on the inside of the lower lid. Most of the computer's internal hardware is fitted inside the lower lid enclosure under the keyboard, although many modern laptops have a built-in webcam at the top of the screen, and some even feature a touchscreen display. In most cases, unlike tablet computers which run on mobile operating systems, laptops tend to run on desktop operating systems, which were originally developed for desktop computers.

The word laptop, modeled after the term desktop (as in desktop computer), refers to the fact that the computer can be practically placed on the user's lap; while the word notebook refers to most laptops sharing a form factor with paper notebooks. As of 2024, in American English, the terms laptop and notebook are used interchangeably; in other dialects of English, one or the other may be preferred. The term notebook originally referred to a type of portable computer that was smaller and lighter than mainstream laptops of the time, but has since come to mean the same thing and no longer refers to any specific size.

Laptops are used in a variety of settings, such as at work (especially on business trips), in education, for playing games, web browsing, for personal multimedia, and for general home computer use. They can run on both AC power and rechargable battery packs and can be folded shut for convenient storage and transportation, making them suitable for mobile use. Laptops combine many of the input/output components and capabilities of a desktop computer into a single unit, including a display screen (usually 11–17 in or 280–430 mm in diagonal size), small speakers, a keyboard, and a pointing device (namely compact ones such as touchpads or pointing sticks). Hardware specifications may vary significantly between different types, models, and price points.

Design elements, form factors, and construction can also vary significantly between models depending on the intended use. Examples of specialized models of laptops include 2-in-1 laptops, with keyboards that either be detached or pivoted out of view from the display (often marketed having a "laptop mode"); rugged laptops, for use in construction or military applications; and low-production-cost laptops such as those from the One Laptop per Child (OLPC) organization, which incorporate features like solar charging and semi-flexible components not found on most laptop computers. Portable computers, which later developed into modern laptops, were originally considered to be a small niche market, mostly for specialized field applications, such as in the military, for accountants, or travelling sales representatives. As portable computers evolved into modern laptops, they became widely used for a variety of purposes.

With or WITH may refer to:

• With, a preposition in English
• Carl Johannes With (1877–1923), Danish doctor and arachnologist
• With (character), a character in D. N. Angel
• With (novel), a novel by Donald Harrington
• With (album), a 2014 album by TVXQ
• With (EP), a 2021 EP by Nam Woo-hyun