camlquery.ViewXml syntax question in client object model

Hello,

While retrieving items from list using CAML query, someone had used below syntax:

camlQuery.ViewXml =@"<View><Query><Where><Eq><FieldRef Name='Name'/><Value Type='Text'>Shailesh</Value></Eq></Where></Query></View>";

And someone used below:

CamlQuery camlQuery = new CamlQuery();  
camlQuery.ViewXml = "<View><Query><Where><Geq><FieldRef Name='ID'/>" +"<Value Type='Number'>19</Value></Geq></Where></Query><RowLimit>100</RowLimit></View>";

So, I have general(may be stupid, but not aware of..so) questions as,

1. Why "@" in one query, and not in another?

2. why SP.CamlQuery in first query and CamlQuery in another while declaring object

Please advice.

Thanking you in advance.

Regards,

Jayashri