Both of the methods displayed search in a specified folder and, if selected, the children folders.
The top method returns all objects that match.
Example in C#
// Returns: IEnumerable<BaseInfo>
var baseInfo = await client.SearchAsync(FolderInfo folder, String query, Int32 page, Int32 pageSize, Boolean includeChildFolders, Boolean spanScope, String forTags, Int32 limit, Boolean includeParents, String collationLocale, Int32 collationStrength, String hints, Boolean useTwoStageQuery, Int32 firstStageCandidateLimit);