From the spring specs, there are five types of bean scopes supported :
1. singleton(default*)
Scopes a single bean definition to a single object instance per Spring
IoC container.2. prototype
Scopes a single bean definition to any number of object instances.
3. request
Scopes a single bean definition to the lifecycle of a single HTTP
request; that is each and every HTTP request will have its own
instance of a bean created off the back of a single bean definition.
Only valid in the context of a web-aware Spring ApplicationContext.4. session
Scopes a single bean definition to the lifecycle of a HTTP Session.
Only valid in the context of a web-aware Spring ApplicationContext.5. global session
Scopes a single bean definition to the lifecycle of a global HTTP
Session. Typically only valid when used in a portlet context. Only
valid in the context of a web-aware Spring ApplicationContext.
*default means when no scope is explicitly provided in the <bean /> tag.
read more about them here: http://static.springsource.org/spring/docs/3.0.0.M3/reference/html/ch04s04.html