C# fixed method

Question

Hi I am new to c#.NET. I have a problem with fixed method in C#.NET. I cann't understandard what does the following code means. Please anyone can explain this In my code unsafe { fixed(sbyte * sp = ByteValue); String newinstance = new String(sp); } whereas ByteValue is sbyte data type. Please explain the unsafe and fixed method Thanks in Advance. Regards R.Ravikumar