If a place comes alive, it becomes filled with activity.

The city centre really comes alive at the weekend. 到了周末，市中心就变得十分热闹。

If you make something come alive, you make it seem real and interesting.

She's a writer who really knows how to make her characters come alive. 她是一位真正懂得如何把人物塑造得栩栩如生的作家。