And vise vers, i.e.: convert type 'string'  to 'byte[]'

The method GetString of the right Encoding instance.
For the other direction use GetBytes.

In either case, you have to know the right encoding

Christof

That entirely depends on what the data is. If it's intrinsically text
data, you should pick the right encoding and use Encoding.GetString.

If it's arbitrary binary data that you want to preserve as a string
and then convert back to binary data later, use Convert.ToBase64String
and Convert.FromBase64String.

Jon

Assuming the data is in a format and encoding that will correctly convert,
you can use shorthand static methods like:

string myString =System.Text.Encoding.UTF8.GetString(myByteArray);
and
byte[] myByteArray = System.Text.Encoding.UTF8.GetBytes(myString);