The Oboe is a 'C' instrument, whereas the cor anglais in a transposing 'F' instrument. Here you can find their written and sounding ranges.
Oboe and Cor Anglais
In the clip to the right, Philharmonia players discuss the ranges of the oboe and the cor anglais. They discuss the subject of listenability and playability of some of the more extreme parts of each instruments range, as well as the more comfortable and welcoming mid-range sections.