Commentary on Heidegger's Being and Time: The Worldhood of the World pp. 102-22

World is what we colloquially call context. Equipment is all the stuff around us. Heidegger uses the word equipment to point up the fact that most of the things in our environment have an instrumental function. As I write this, I have a paperback copy of Being and Time resting on my belly, and though I'm not using it to read, it is a thing at-hand, ready to be used, whether to read or swat a mosquito.

Our world is already in advance full of equipment imbued with significance, and we take this environment and these things mostly for granted. That's our nature. Only when the stuff malfunctions do I tend to take notice.