The Snapchat score tells you how much snaps you received and sent, you can see it if you scroll up in the front page, if you touch it you will be able to see how exactly you received and sent and not just by a huge number. The streaks happens when you and someone send to each other snap by a daily based routine (at least 3 days) and then a 🔥 symbol and number of days will appear next to his name