Containers.Item1 Choose your containers with care

• The standard STL sequence containers, vector, string, deque, and list.
• The standard STL associative containers, set, multiset, map and multimap.
• The nonstandard  sequence  containers  slist  and  rope.  slist  is  a  singly  linked  list, and rope is essentially a heavy-duty string. 
• The  nonstandard  associative  containers  hash_set,  hash_multiset,  hash_map,  and hash_multimap.
Contiguous-memory  containers  (also  known  as  array-based  containers]  store  their  elements  in  one  or  more  (dynamically  allocated)  chunks  of  memory,  each  chunk  holding  more  than  one  container  element.  If  a  new  element  is  inserted  or  an  existing  element is erased, other elements in the same memory chunk have to be shifted up ordown to make room for the new element or to fill the space formerly occupied by theerased element. This kind of movement affects both performance (see Items 5 and 14) and exception safety (as we'll soon see). The standard contiguous-memory containers are  vector,  string,  and  deque.  The  nonstandard  rope  is  also  a  contiguous-memory  container.
Node-based   containers   store   only   a   single   element   per   chunk   of   (dynamically   allocated) memory. Insertion or erasure of a container element affects only pointers to nodes, not the contents of the nodes themselves, so element values need not be moved when something is inserted or erased. Containers representing linked lists, such as list and  slist,  are  node-based,  as  are  all  the  standard  associative  containers. typically  implemented  as  balanced  trees.)