A sequence is a container that organizes a set of objects, all the same type, into a linear arrangement. vector, list, deque, and string fall into this category.
Sequences offer different complexity trade-offs. vector offers fast inserts and deletes from the end of the container. deque is useful when insertions and deletions will take place at the beginning or end of the sequence. Use list when there are frequent insertions and deletions from the middle of the sequence.
For more information about sequences and their requirements, see the Containers section of this reference guide, or see the section on the specific container.