What is United Airlines Baggage Policy?

Yes, as long as it doesn't exceed 9 x 14 x 22 inches. It can be either your carry-on or personal item.

Any bag over 50 pounds (23 kg) incurs a $100 charge. Even one pound over triggers the fee.

No, they're separate allowances. You get both a carry-on and a personal item for most fares.

Yes, Basic Economy to South America, Atlantic, or Pacific routes include a free checked bag, unlike domestic Basic Economy.

Yes, containers up to 3.4 ounces (100 mL) are allowed in a clear quart-size bag per TSA rules.