Rust: What is the difference between File::open and tokio::fs::File::open?

File::open — blocking. tokio::fs::File::open — async.

File::open:

• Blocking.
• Blocks thread.
• For sync code.

tokio::fs::File::open:

• Async.
• Non-blocking.
• For async code.

1// Blocking
2let file = std::fs::File::open("file.txt")?;
3
4// Async
5let file = tokio::fs::File::open("file.txt").await?;

Key: std::fs for blocking, tokio::fs for async.