Is the personal hotspot option on the iphone safe?

I just learned i can use my iphone as a hotpot and i freaked out! Apparently you go settings, general, network, the it says personal hotspot! So is it safe? More importantly does it cost a lot or free?

It is safe, you can share your network with others. It does cost to have that activated, by checking it costs $20/month with 2GB shareable data.