NETGEAR AC1900 (24×8) WiFi Cable Modem Router C7000, DOCSIS 3.0 | Certified for XFINITY by Comcast, Spectrum, Cox, and more (C7000-100NAS)

0 (zero) is a number representing an empty quantity. Adding (or subtracting) 0 to any number leaves that number unchanged; in mathematical terminology, 0 is the additive identity of the integers, rational numbers, real numbers, and complex numbers, as well as other algebraic structures. Multiplying any number by 0 results in 0, and consequently division by zero has no meaning in arithmetic.

As a numerical digit, 0 plays a crucial role in decimal notation: it indicates that the power of ten corresponding to the place containing a 0 does not contribute to the total. For example, "205" in decimal means two hundreds, no tens, and five ones. The same principle applies in place-value notations that uses a base other than ten, such as binary and hexadecimal. The modern use of 0 in this manner derives from Indian mathematics that was transmitted to Europe via medieval Islamic mathematicians and popularized by Fibonacci. It was independently used by the Maya.

Common names for the number 0 in English include zero, nought, naught (), and nil. In contexts where at least one adjacent digit distinguishes it from the letter O, the number is sometimes pronounced as oh or o (). Informal or slang terms for 0 include zilch and zip. Historically, ought, aught (), and cipher have also been used.

Year 215 (CCXV) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Laetus and Sulla (or, less frequently, year 968 Ab urbe condita). The denomination 215 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious and cultural significance in many societies.

Comcast Corporation, formerly known as Comcast Holdings, is an American multinational telecommunications and media conglomerate incorporated and headquartered in Philadelphia.

It is the fourth-largest broadcasting and cable television company worldwide by revenue (behind China Mobile, Verizon, and AT&T). It is the third-largest pay-TV company, the second-largest cable TV company by subscribers, and the largest home Internet service provider in the United States. In 2023, the company was ranked 51st in the Forbes Global 2000. Comcast is additionally the nation's third-largest home telephone service provider. It provides services to U.S. residential and commercial customers in 40 states and the District of Columbia. As the owner of NBCUniversal since 2011, Comcast is also a high-volume producer of films for theatrical exhibition and television programming, and a theme parks operator. It is the fourth-largest telecommunications company by worldwide revenue.

Comcast owns and operates the Xfinity residential cable communications business segment and division; Comcast Business, a commercial services provider; and Xfinity Mobile, an MVNO of Verizon. Through NBCUniversal, Comcast is also the owner and operator of over-the-air national broadcast network channels such as NBC, Telemundo, TeleXitos, and Cozi TV; multiple cable-only channels such as MSNBC, CNBC, USA Network, Syfy, Oxygen, Bravo, and E!; the film studio Universal Pictures; the VOD streaming service Peacock; animation studios DreamWorks Animation, Illumination, and Universal Animation Studios; and Universal Destinations & Experiences. It also has significant holdings in digital distribution, such as thePlatform, which it acquired in 2006; and ad-tech company FreeWheel, which it acquired in 2014. Since October 2018, Comcast is also the parent company of Sky Group.

Comcast is criticized and put under intense public scrutiny for a variety of reasons. Its customer satisfaction ratings were among the lowest in the cable industry during the years 2008–2010. It has violated net neutrality practices in the past and despite its commitment to a narrow definition of net neutrality, critics advocate a definition that precludes any distinction between Comcast's private network services and the rest of the Internet. Critics also point out a lack of competition in the vast majority of Comcast's service areas; in particular, the limited competition among cable providers. Given its negotiating power as a large ISP, some suspect that it could leverage paid peering agreements to unfairly influence end-user connection speeds. Its ownership of both content production (in NBCUniversal) and distribution (as an ISP) has raised antitrust concerns. These issues and others led to Comcast being dubbed "The Worst Company in America" by The Consumerist in 2010 and 2014.

Cox or COX may refer to:

• Cox (surname), including people with the name

Data Over Cable Service Interface Specification (DOCSIS) is an international telecommunications standard that permits the addition of high-bandwidth data transfer to an existing cable television (CATV) system. It is used by many cable television operators to provide cable Internet access over their existing hybrid fiber-coaxial (HFC) infrastructure.

DOCSIS was originally developed by CableLabs and contributing companies, including Arris, BigBand Networks, Broadcom, Cisco, Comcast, Conexant, Correlant, Cox, General Instrument, Harmonic, Intel, Motorola, Netgear, Terayon, Time Warner Cable, and Texas Instruments.

A modulator-demodulator, commonly referred to as a modem, is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more carrier wave signals to encode digital information, while the receiver demodulates the signal to recreate the original digital information. The goal is to produce a signal that can be transmitted easily and decoded reliably. Modems can be used with almost any means of transmitting analog signals, from LEDs to radio.

Early modems were devices that used audible sounds suitable for transmission over traditional telephone systems and leased lines. These generally operated at 110 or 300 bits per second (bit/s), and the connection between devices was normally manual, using an attached telephone handset. By the 1970s, higher speeds of 1,200 and 2,400 bit/s for asynchronous dial connections, 4,800 bit/s for synchronous leased line connections and 35 kbit/s for synchronous conditioned leased lines were available. By the 1980s, less expensive 1,200 and 2,400 bit/s dialup modems were being released, and modems working on radio and other systems were available. As device sophistication grew rapidly in the late 1990s, telephone-based modems quickly exhausted the available bandwidth, reaching 56 kbit/s.

The rise of public use of the internet during the late 1990s led to demands for much higher performance, leading to the move away from audio-based systems to entirely new encodings on cable television lines and short-range signals in subcarriers on telephone lines. The move to cellular telephones, especially in the late 1990s and the emergence of smartphones in the 2000s led to the development of ever-faster radio-based systems. Today, modems are ubiquitous and largely invisible, included in almost every mobile computing device in one form or another, and generally capable of speeds on the order of tens or hundreds of megabytes per second.

Router may refer to:

• Router (computing), a computer networking device
• Router (woodworking), a rotating cutting tool
• Router plane, a woodworking hand plane

A spectrum (pl.: spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word spectrum was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum. It thereby became a mapping of a range of magnitudes (wavelengths) to a range of qualities, which are the perceived "colors of the rainbow" and other properties which correspond to wavelengths that lie outside of the visible light spectrum.

Spectrum has since been applied by analogy to topics outside optics. Thus, one might talk about the "spectrum of political opinion", or the "spectrum of activity" of a drug, or the "autism spectrum". In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad range of conditions or behaviors grouped together and studied under a single title for ease of discussion. Nonscientific uses of the term spectrum are sometimes misleading. For instance, a single left–right spectrum of political opinion does not capture the full range of people's political beliefs. Political scientists use a variety of biaxial and multiaxial systems to more accurately characterize political opinion.

In most modern usages of spectrum there is a unifying theme between the extremes at either end. This was not always true in older usage.