Some folders have a lock to prevent accidentally closing. Some do not. Sent from my SM-G930VL using Tapatalk
If it is like a small folding knife like a Swiss army knife, then nothing stops it from folding. I have a larger Gerber folding knife and it has a piece that falls into place to prevent the blade from closing until you move it out of the way. It is called a locking blade.
I had a knife that had a liner lock that was a wimpy spring steel flat that popped into the mechanism and just needed a push to the side to unlock. Notice, had. After 2 close calls and a good slice across my fingers on #3, it was out. Got a pre buy out Cold Steel company Recon 1 model. Supposedly the strongest 3 points of lock mechanism in the folding market. I love it, but have heard no reviews since the buy out.
I have some older cold steel knives also. Some fixed blade and one folder locking blade. I like their knives.