What is the benefit of using IQueryable and LINQ queries? -

i have project realized own configuration classes:

iconsizesconfigsection: configurationsection iconsizescollection: configurationelementcollection iconsize: configurationelement 

in config class exists property:

public iqueryable<iconsize> iconsizes     {                  {             iconsizesconfigsection configinfo = (iconsizesconfigsection)configurationmanager.getsection("iconconfig");             return configinfo.iconsizes.oftype<iconsize>().asqueryable<iconsize>();           }     } 

iconsizes property returns iconsizescollection derives configurationelementcollection. in turn configurationelementcollection derives icollection, ienumerable.

in class have such code:

var previewiconsize = config.iconsizes.firstordefault(c => c.name == "avatarsize"); 

why in such case uses deffered execution? why uses asqueryable<iconsize>() collection , uses linq , deffered execution?

is there benefits compared using simple list?

in these case, there no practical benefit. using iqueryable helpful cases when query rewriting/translation optimize performance. incur decreased performance in provided example.

one example of using iqueryable in helpful way significant performance increase gained when lazily translating , evaluating queries against database or web service. perform better alternative of pulling massive result sets , applying query logic in active memory "simple list".

the way can tell using iqueryable in case detrimental collection loaded memory, when begin query.