A segment of memory gets put aside for storing data in that will be needed in a process. The dfata can be anything depending on the process. The segment of memory is called a stack (just like a stack of plates or anything else). The stack is divided into sections of uniform size called pages. If you are trying to manage a LOT of memory, it can be faster to tell the computer to find something on the third line of page thirteen, than to tell ti to find it at row X column Y or a number indicating the sequential location of that memory location. Being out of pages means that some process has loaded up your memory until there are no more allocated places to store anymore data into.

A pipe is a _logical_ connection between two processes -- for example a process of getting all the data your enquiry calls for, and another process of assembling that data into an HTML page, and another process for translating that HTML into packets of data with headers as required by the communication protocol, and another process for taking those packets off the stack and sending them. If th logical pipe is broken then the first process has no way to send the data to the second process and everything grinds to a halt.

Functionally a pipe works like a pipe does physically -- a stream going in one end goes straight to the other end and comes out there.

A