C#: What is the difference between MemoryStream and FileStream?

MemoryStream — in-memory. FileStream — disk.

MemoryStream:

• In-memory.
• Fast.
• No persistence.

FileStream:

• Disk.
• Slower.
• Persistent.

1// MemoryStream
2using var ms = new MemoryStream();
3await ms.WriteAsync(data);
4ms.Position = 0;
5
6// FileStream
7using var fs = File.Create("file.txt");
8await fs.WriteAsync(data);

Key: MemoryStream for temp, FileStream for persistence.