What Is A Ridge Filler And Do I Need To Use One?

I will admit it that up until a few days ago I had no clue what the heck a ridge filler was. I knew it was something for nails but didn't really understand the purpose of it. Well I have learned what it is from a bad nail experience. I scuffed up my nail pretty bad and any polish I put on looked awful. This is where a ridge filler comes in.
A ridge filler can be used on a clean nail bed or with acrylic nails to hide your natural nail showing. You would use a ridge filler on a natural nail to even the nail bed out, which is exactly what I needed to do. I wish I had one of these on hand a long time ago, it would have saved me many times. The only one I currently own is OPI Ridge Filler and it works great. Just one thin coat over each nail, give it a few minutes to dry and you can put some polish over it. And now you know what a ridge filler is :)
Have you used a ridge filler before?