Interglacial age (or interglaciation) is a period of time with warm climate between two ice ages. It has temperatures similar to currently observed. The past 2.6 million years the earth has experienced many changes where the climate has fluctuated between glaciations and interglaciations.
We live in an interglaciation, which in Europe is called Holocene. This period with warm climate started about 11.700 years ago when the last ice age ended.