A data structure holding many values, possibly of different types, which is usually accessed sequentially, working from the head to the end of the tail - an "ordered list". This contrasts with a (one-dimensional) array, any element of which can be accessed equally quickly.
Lists are often stored using a cell and pointer arrangement where each value is stored in a cell along with an associated pointer to the next cell. A special pointer, e.g. zero, marks the end of the list. This is known as a (singly) "linked list". A doubly linked list has pointers from each cell to both next and previous cells.
An unordered list is a set.