ouTube is an American online video sharing and social media platform headquartered in San Bruno, California, United States. Accessible worldwide, it was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by Google and is the second most visited website, after Google Search. YouTube has more than 2.5 billion monthly users, who collectively watch more than one billion hours of videos each day. As of May 2019, videos were being uploaded at a rate of more than 500 hours of content per minute.In October 2006, YouTube was bought by Google for $1.65 billion. Goog
e's ownership of YouTube expanded the site's business model, expanding from generating revenue from advertisements alone to offering paid content such as movies and exclusive content produced by YouTube. It also offers YouTube Premium, a paid subscription option for watching content without ads. YouTube also approved creators to participate in Google's AdSense program, which seeks to generate more revenue for both parties. YouTube reported revenue of $29.2 billion in 2022. In 2021, YouTube's annual advertising revenue increased to $28.8 billion, an increase in revenue of 9 billion from the previous year.Since its purchase by Google, YouTube has expanded beyond the core website into mobile apps, network television, and the ability to link with other platforms. Video categories on YouTube include music videos, video clips, news, short films, feature films, songs, documentaries, movie trailers, teasers, live streams, vlogs, and more. Most content is generated by individuals, including collaborations between YouTubers and corporate sponsors. Established media corporations such as Disney, Paramount, NBCUniversal, and Warner Bros. Discovery have also created and expanded their corporate YouTube channels to advertise to a greater audience. YouTube has had unprecedented social impact, influencing popular culture, internet trends, and creating multimillionaire celebrities. Despite its growth and success, it has been widely criticized for allegedly facilitating the spread of misinformation and the sharing of copyrighted content, routinely violating its users' privacy, enabling censorship, and endangering child safety and wellbeing, and for its guidelines and how they are implemented.See More >>>
country is a distinct part of the world, such as a state, nation, or other political entity. It may be a sovereign state or make up one part of a larger state. For example, the country of Japan is an independent, sovereign state, while the country of Wales is a component of a multi-part sovereign state, the United Kingdom. A country may be a historically sovereign area (such as Korea), a currently sovereign territory with a unified government (such as Senegal), or a non-sovereign geographic region associated with certain distinct political, ethnic, or cultural characteristics (such as the Ba
que Country). The definition and usage of the word "country" is flexible and has changed over time. The Economist wrote in 2010 that "any attempt to find a clear definition of a country soon runs into a thicket of exceptions and anomalies." Most sovereign states, but not all countries, are members of the United Nations. The largest country by area is Russia, while the smallest is the microstate Vatican City. The most populous is India, while Vatican City is also the least populous.See More >>>
galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. The word is derived from the Greek galaxias (γαλαξίας), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mas
visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies. Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular. Many are thought to have supermassive black holes at their centers. The Milky Way's central black hole, known as Sagittarius A*, has a mass four million times greater than the Sun. As of March 2016, GN-z11 is the oldest and most distant galaxy observed. It has a comoving distance of 32 billion light-years from Earth, and is seen as it existed just 400 million years after the Big Bang. It is estimated that there are roughly 200 billion galaxies (2×1011) in the observable universe. Most galaxies are 1,000 to 100,000 parsecs in diameter (approximately 3,000 to 300,000 light years) and are separated by distances on the order of millions of parsecs (or megaparsecs). For comparison, the Milky Way has a diameter of at least 26,800 parsecs (87,400 ly) and is separated from the Andromeda Galaxy (with diameter of about 152,000 ly), its nearest large neighbor, by 780,000 parsecs (2.5 million ly.) The space between galaxies is filled with a tenuous gas (the intergalactic medium) with an average density of less than one atom per cubic meter. Most galaxies are gravitationally organized into groups, clusters and superclusters. The Milky Way is part of the Local Group, which it dominates along with Andromeda Galaxy. The group is part of the Virgo Supercluster. At the largest scale, these associations are generally arranged into sheets and filaments surrounded by immense voids. Both the Local Group and the Virgo Supercluster are contained in a much larger cosmic structure named Laniakea.See More >>>
tutorial, in education, is a method of transferring knowledge and may be used as a part of a learning process. More interactive and specific than a book or a lecture, a tutorial seeks to teach by example and supply the information to complete a certain task. A tutorial can be taken in many forms, ranging from a set of instructions to complete a task to an interactive problem solving session (usually in academia).