MacBook Air keyboard glowing intermittently

So recently my MacBook Air’s keyboard started to stop glowing for 1 second then it turns back to normal and it just repeats this action. I find it strange because it doesn’t usually do this. Why?

[Re-Titled by Moderator]

Original Title: Is it normal for my MacBook Air’s keyboard to glow then it stops glowing for a sec then it turns back to normal continuously?