Spring offers four types of collection configuration elements which are as follows:
list: This helps in wiring i.e. injecting a list of values, allowing duplicates.
set: This helps in wiring a set of values but without any duplicates.
map: This can be used to inject a collection of name-value pairs where name and value can be of any type.
props: This can be used to inject a collection of name-value pairs where the name and value are both Strings.