The name currant is used to refer to two distinctly different fruits, one fresh, one dried.
The dried one is a small dark seedless raisin from the Zante grape, often used in baking. You may have had them in Eccles cakes.
The fresh one is a wee tart black, white, or red berry which is related to the gooseberry. The black ones are used for preserves, syrups and liqueurs (notably cassis), as well as lambic beer). The red or white ones can be eaten as is or used for pies, preserves, or sauces. Currant bushes grow throughout Europe and North America, and First Nations people used dried currants (from the berries, not the grapes) to make pemmican.
A blister rust has infected many currant bushes in North America; it's incurable, and when it's found, the plants are destroyed. This is causing the disappearance of native currants from some areas of the continent.