My friend applied to 200 tech jobs in two years. No CS degree. Not one callback.
Last month Anthropic offered him $750,000.
All because of one free Stanford lecture. One hour.
A Stanford professor explains how ChatGPT actually works. Not the Twitter version. The real one.
He watched it in bed. Paused it eleven times. After that hour he told me something I didn't believe. "It's embarrassingly simple."
Three days later he applied to Anthropic.
Every single question they asked him, he knew from that video.
Detailed Answer:
1. Concurrency (Dealing with many things)
Concurrency is about structure. It’s the ability of a system to handle multiple tasks by switching between them. You aren't necessarily doing them at the exact same time, but you’re making progress on all of them.
• Example: A waiter at a restaurant. They take an order, drop off a bill, and refill a water glass. They aren't doing all three at once, but they are managing all those "tasks" concurrently.
2. Parallelism (Doing many things)
Parallelism is about execution. It’s literally doing multiple things at the exact same millisecond. This requires hardware with multiple cores.
• Example: Four waiters working at four different tables. Each waiter is performing a task simultaneously. This is true "parallel" work.
3. Multithreading (The "How")
Multithreading is the tool we use to achieve the two above. A thread is just a sequence of instructions. By spawning multiple threads, we tell the OS we have different units of work to do.
• Example: In a kitchen, a "thread" is a specific recipe. Multithreading is having multiple recipes open on the counter. If you have one chef, they switch between them (Concurrency). If you have multiple chefs, they cook the recipes at once (Parallelism).
Concurrency is about interrupting one task to work on another (Managing).
• Parallelism is about replicating the effort to work on both (Simultaneous).
• Multithreading is the mechanism (The workers/threads) you use to get there.