What was the Vel d'Hiv Roundup mentioned in this book?

Beginning at 4:00 a.m. on the 16th of July 1942, 13,152 Jews were arrested according to records of the Préfecture de police, of which 5,802 were women and 4,051 were children. An unknown number of people were warned by the French Resistance or hidden by neighbors, deliberate or accidental, some policemen escaped being rounded-up. Conditions for the arrested were harsh. They could take only a blanket, a sweater, a pair of shoes and two shirts with them. Most families were split-up and never reunited. They were taken to wait in a window-less building with no food or water, or bathrooms for 4 days.

After arrest, some Jews were taken by bus to an internment camp in an incomplete complex of apartments and apartment towers in the northern suburb of Drancy. Others were taken to the Vélodrome d'hiver in the 15th arrondissement, which had already been used as a prison in a roundup in the summer of 1941.

This picture shows the internment camp at Drancy, outside Paris, where Jews were confined until they were deported to the death camps.