Add Field Attribute to SharepointList (Library) - sharepoint

Question

I get list Metadata for different SharepointLists from calling the Lists-Webservice:
[DocTemplateUrl] =>
[DefaultViewUrl] =>
[MobileDefaultViewUrl] =>
[ID] => {D33D2DEF-1404-4007-8D79-EE9EF75E5AC4}
[Title] => appdata
[Description] =>
[ImageUrl] => /_layouts/15/images/itgen.png?rev=23
[Name] => {D33D2DEF-1404-4007-8D79-EE9EF75E5AC4}
[BaseType] => 0
[FeatureId] =>
[ServerTemplate] => 125
[Created] => 20141006 14:46:58
[Modified] => 20141006 14:46:58
[LastDeleted] => 20141006 14:46:58
[Version] => 0
[Direction] => none
[ThumbnailSize] =>
[WebImageWidth] =>
[WebImageHeight] =>
[Flags] => 20756
[ItemCount] => 0
[AnonymousPermMask] => 0
[RootFolder] =>
[ReadSecurity] => 1
[WriteSecurity] => 1
[Author] => 3
[EventSinkAssembly] =>
[EventSinkClass] =>
[EventSinkData] =>
[EmailAlias] =>
[WebFullUrl] => /
[WebId] => 1f8e1fa6-d3fa-4393-98f5-deb4b3c89040
[SendToLocation] =>
[ScopeId] => 5c1f32b6-cb59-4ac8-b5ba-4eac5788c671
[MajorVersionLimit] => 0
[MajorWithMinorVersionsLimit] => 0
[WorkFlowId] =>
[HasUniqueScopes] => False
[NoThrottleListOperations] => False
[HasRelatedLists] =>
[Followable] => False
[AllowDeletion] => False
[AllowMultiResponses] => False
[EnableAttachments] => True
[EnableModeration] => False
[EnableVersioning] => False
[HasExternalDataSource] => False
[Hidden] => True
[MultipleDataList] => False
[Ordered] => False
[ShowUser] => True
[EnablePeopleSelector] => False
[EnableResourceSelector] => False
[EnableMinorVersion] => False
[RequireCheckout] => False
[ThrottleListOperations] => False
[ExcludeFromOfflineClient] => False
[CanOpenFileAsync] => True
[EnableFolderCreation] => True
[IrmEnabled] => False
[IsApplicationList] => False
[PreserveEmptyValues] => False
[StrictTypeCoercion] => False
[EnforceDataValidation] => False
[MaxItemsPerThrottledOperation] => 5000
Is it possible to add a new field to a list in Sharepoint? I don't want to add a column for the document attributes in a list, but add a field as a list metadata to retrieve it with the lists-webservice.
THX!

Answer 1

You can add existing site column, create a new site column, create a new list column and so on. Just pick your preference, in any normal case your would like to create a site column.
This can be done either by code, powershell or the SharePoint gui
PowerShell, http://adicodes.com/add-fields-to-list-with-powershell-in-sharepoint-2010/
Gui, https://www.youtube.com/watch?v=rvPDZ598Xxk
Code, http://msdn.microsoft.com/en-us/library/office/ms437580(v=office.15).aspx
But since you are asking this I suggest you keep to the GUI until you learn a bit more on SharePoint