A peroxide is a compound containing an oxygen–oxygen single bond or the peroxide anion ([O−O]^2–). The O−O group is called the peroxide group or peroxo group. In contrast to oxide ions, the oxygen atoms in the peroxide ion have an oxidation state of −1.

The simplest stable peroxide is hydrogen peroxide. Superoxides, dioxygenyls, ozones and ozonides compound are considered separately. Peroxide compounds can be roughly classified into organic and inorganic. Whereas the inorganic peroxides have an ionic, salt-like character, the organic peroxides are dominated by the covalent bonds. The oxygen-oxygen chemical bond of peroxide is unstable and easily split into reactive radicals via homolytic cleavage. For this reason, peroxides are found in nature only in small quantities, in water, atmosphere, plants, and animals.

Peroxides have a bleaching effect on organic substances and therefore are added to some detergents and hair colorants. Other large-scale applications include medicine and chemical industry, where peroxides are used in various synthesis reactions or occur as intermediate products. With an annual production of over 2 million tonnes, hydrogen peroxide is the most economically important peroxide. Many peroxides are unstable and hazardous substances; they cannot be stored and therefore are synthesized in situ and used immediately.

The Cure are an English alternative rock band formed in Crawley, West Sussex in 1976. The band has experienced several line-up changes, with frontman, vocalist, guitarist and principal songwriter Robert Smith being the only constant member. The Cure first began releasing music in the late 1970s with its debut album Three Imaginary Boys (1979); this, along with several early singles, placed the band as part of the post-punk and New Wave movements that had sprung up in the wake of the punk rock revolution in the United Kingdom. During the early 1980s, the band's increasingly dark and tormented music helped form the gothic rock genre.

After the release of Pornography (1982), the band's future was uncertain and Smith was keen to move past the gloomy reputation his band had acquired. With the 1982 single "Let's Go to Bed" Smith began to place a pop sensibility into the band's music (as well as a unique stage look). The Cure's popularity increased as the decade wore on, especially in the United States where the songs "Just Like Heaven", "Lovesong" and "Friday I'm in Love" entered the Billboard Hot 100 chart. By the start of the 1990s, The Cure were one of the most popular alternative rock bands in the world. The band is estimated to have sold 27 million albums as of 2004. The Cure have released thirteen studio albums, 10 EPs and over thirty singles during the course of their career. Since 2010, they have been working on a fourteenth studio album.