Load vs Load Query in SharePoint

Load 

Load() populate the client object directly with what it gets data from the server i.e. a collection eg. ListItemCollection. Means Load() returns ListCollection.

LoadQuery

LoadQuery() returns the data as a new collection in IEnumerable format.

LoadQuery() is flexible than Load() when you are working with more than one query because LoadQuery() returns data in IEnumerable<> format which is easy to access.