XML & Binary Serialization C#

The Binary serialization is fast but serialization and deserialization is language dependent while the XML serialization is platform/language independent.

FileStream fs = new FileStream("Ser.Data, FileMode.Create");
BinaryFormatter bf = new BinaryFormatter();
bf.Serialized(fs, "data");

FileStream fs = new FileStream("Ser.Data, FileMode.Open");
string data = (string) bf.Deserialized(fs);
fs.Close();

[Serialized]
[NonSerialized]
[OptionalFieled] -Use for newly added fields when try to deserialize an old instance of class

===================================================
FileStream fs = new FileStream("Ser.Data, FileMode.Create");
XmlSerializer xs = new XmlSerializer(typeOf(string));
xs.Serialize(fs, "string1");

FileStream fs = new FileStream("Ser.Data, FileMode.Open");
strig str = (string)xs.Deserialize(fs);
fs.Close();

[XmlRoot]
[XmlAttribute]
[XmlIgnore]