1 additional people who provide help when it is needed: The police officer requested some backup when the shooting began.
az: dəstək, yardım; ehtiyatda olan qüvvə
ru: резерв; подкрепление
2 (computing) a copy of a computer file that can be used in case the original is destroyed: You should always make a backup of the file you are working on.
az: əlavə (ehtiyat) nüsxə
ru: резервная копия
3 a piece of equipment, a system etc that can be used when there is a problem with the original one: We have a generator which we use as a backup if the power fails; (also adjective) a backup plan.
az: əvəzedici, əlavə, yardımçı
ru: дублирующий вариант