Help me understand health insurance?

[ASIAN JUL]

So, can anyone school a n00b on health insurance? I've been looking into personal health insurance since my work doesn't cover it. I found this plan, it was called the Keystone HMO $20 CoPay plan and I found it on ehealthinsurance.com

It almost sounds too good to be true with no annual deductible and only $20 co-pays for a primary physician. The plan got a 4.5 out of 5 rating, though.

Plan Type
HMO

Office Visit for Primary Doctor
$20 Copay

Office Visit for Specialist
$30 Copay

Coinsurance
None

Annual Deductible
None

Separate Prescription Drugs Deductible
$250 Individual
$750 Family

Prescription Drugs
Generic: $15 Copay after prescription deductible
Brand: $25 Copay after prescription deductible
Non-Formulary: $35 Copay after prescription deductible

Annual Out-of-Pocket Limit
None

Lifetime Maximum
Unlimited

Health Savings Account (HSA) Eligible
No

Out-of-Network Coverage
No

Out of Country Coverage
Yes. Emergency and Urgent Care Only through BlueCard Worldwide

No idea if I'll be approved for it, but before I jump the gun I was wondering if anyone could explain how this works in simple terms?

Thanks