Optical disc composed of a phase change material, most often AgInSbTe, an alloy of silver, indium, antimony, and tellurium. Optical discs are most commonly used for storing music (e.g. for use in a CD player), video (e.g. for use in a Blu-ray player), or data and programs for personal computers (PC). The Optical Storage Technology Association (OSTA) promotes standardized optical storage formats. Although optical discs are more durable than earlier audio-visual and data storage formats, they are susceptible to environmental and daily-use damage. Libraries and archives enact optical media preservation procedures to ensure continued usability in the computer's optical disc drive or
What Is to Be Done? what Lenin’s real views were". Therefore, Lih argues, the word спонтанность, when translated as "spontaneity", distorts his views and has different contextual connotations; how конспирация does not mean "conspiracy", but "the rules and procedures needed for an underground organisation to survive"; тред-юнионизм does not mean "trade unionism", but non-revolutionary "only trade unionism"; and революционер по профессии should not be translated as "professional revolutionary". What Is to Be Done? What Is To Be Done? Burning Questions of Our Movement () is a political pamphlet written by the Russian revolutionary Vladimir Lenin (credited as N. Lenin) in 1901 and published in 1902.