Most of the flights are airlines flights. If you have your private jet it won't be an airline flight, or if your friend has a plane and take you in a flight with him - this won't be an airline flight either.
Airline flight means that there's a company that has it's planes and they are making regular or charter, domestic r international flight carrying their clients from one point of the world to another. It also means that you will need a ticket, probably a visa and some other documents. Then you'll have to arrive in the airport and do it on time, pas a registration and custom procedures and only then you'll get on board.
Let's start with the ticket. Usually it consists of four flying coupons. Each flight - to a transfer than to the destination has it's own separate coupon. Plus the return coupons. If you are flying non-stop the spare coupons will have a note "void" in the rout column.
The last coupon is white and it's a copy that you leave for yourself, but without it all other coupons are invalid.
A coupon is stick to the airline company blank with the luggage receipt. A ticket contains full information of you flight (unfortunately except the information about sights of interest): there you will find everything about the date of the flight, the time of departure and lending, precise information about your tariff and all the restrictions and rules that follow that and etc.
The registration on the flight usually starts three hours before the plane is supposed to take off. Find out all the information about when the registration stops because if you don't appear on time an airline company can use your seat in it's own purposes. The time of boarding will be announced in the airport, when starts you are supposed to come to your entrance and pass the special control.
A passenger is considered to be late if he hasn't passed the registration forty minutes before the plane is taking off. If you see that the registration is coming to an end hurry to the special racks for passengers who are late.
If the plane is charter and you got relatives and friends already on board than a plane can be even delayed a little, but you'd better arrive on time and not hope for this. In case the plane took off without you - your further destiny can be different. If you have the first business class tickets you'll be able to fly with the very next flight in case are left spare places of course. If you have a fixed date on your ticket you'll have to pay a fee to exchange it, in you got a special tariff ticket - you'll have to buy a new one and probably for the full price.
All airline companies agree to deliver to the destination a kid without parents - it's useful if you want send your child to you relatives or friend and have no opportunity to escort him/her.
Different airline companies agree to take children alone on board only if they've reach some fixed age - usually its two years. In the special form where you fill all the information about the child and about those who we'll be receiving the child. Then in the airport you pass the kid to the representative on the airline with whom the child passes all the registration and other procedures.
On board all the personnel will be keeping eye on the child and will be doing everything to make a flight comfortable for the little one. In the airport the child will be given into the hands of the receiving side but only in case that side will be able to approve it's identity.
Also you can take pets on airline flights with you. But this will cost you some money and a lot of fuss.
Airline flights tend to be more and more safe and comfortable nowadays, but the personnel surrounds you will care and love only after you get on board. All the procedures preceding and proceeding that can be rather annoying and take even more time when the flight itself. So that sometimes you even start dreaming of your own personal small plane or just a couple of wings.