What is guitar scales?? Should i learn scales?

I'm a beginner and i started off playing electric guitar tabs only and i kind of ditched learning chords. Now i've also realized that there is guitar scales, Therefore , i would like to know is it important to learn scales? Besides, I'm kind of hook up with learning tabs only , so when i try playing scales given on the internet (i'm still bewildered about it). I feel totally lost and bored. One more question is can i just focus on metal scale if metal genre is my favourite???