Generally, there are two types of flights to choose from - Scheduled or Charter. However, regular European holiday charter flight services have reduced considerably in recent years - replaced mostly by low-cost and budget airline scheduled services.

• Schedule flights are when the airline or carrier sells seats on a flight to individual passengers - via various global sales channels. A scheduled airline or carrier offers flight services to a fixed destination on a regular basis, be it hourly, daily, weekly or monthly schedules. The scheduled departure times and routings are usually fixed for a set period of time.
• Charter flights operate differently. Charter flight services are bought from the airline by a customer, company or package tour operator who rents the entire aircraft for a particular purpose; for package tour operators, it's usually as part of a package holiday. A charter flight does not follow a schedule set by the airline or carrier; the customer or holiday tour operator sets the destination and operations to suit their needs.
• Charter flights are (mostly) occupied by package holiday passengers; and with smaller aircraft by private clients. However, you can often book a 'seat-only ticket' on a holiday charter flight by buying the ticket directly from the tour operator.
• Both charter and scheduled airline operators must meet the same safety standards and follow the same strict aviation regulations. The most noticeable difference between scheduled and charter flights is the personalised service, ticket prices, ticket flexibility - plus schedule frequency.
• Please note! Not all Airlines and Charter Operators will operate as above.

Charter airline tickets: Charter and holiday flight seat-only tickets vary in price depending on the time of year, the day of the week, or even the time of departure. Usually, there is only one price for a particular flight, except for last-minute seat sales; this is because most seats on charter flight services 'are sold' on a use-it-or-lose-it basis. If you decide not to travel, claims for a refund from the tour operator can be limited.

Scheduled airline tickets: Scheduled airlines offer a 'wider' range of airfares; your choice of fare will depend on how flexible your needs are - relevant to ticket restrictions. Like holiday charter flights, fares vary according to the time of year or the day you wish to travel - but unlike charter flights, there are usually many different fare types on any one service. The main advantage of scheduled services is the wide choice of routes, flexibility and the range of fares available.

The most expensive fare is the full fare and is usually fully flexible. These fares allow you to change your reservation without penalty or extra charges (except for a nominal administration fee). This ticket may also be endorsable, meaning you may use it with different airlines.

The cheapest scheduled fares are often restricted and non-refundable; between the most expensive and cheapest fares, there's usually a range of alternatives. As a guide - the lower the airfare, the less flexibility you have when making changes. Some cheaper return fares require a stay of at least one Saturday night; some airlines use this requirement to separate business and leisure traveller fares.

Low Cost & Budget airline tickets: Usually, the more in advance you book, the cheaper the airfare.

Ticket conditions for most 'low-cost airlines' tend to be similar in that most tickets will be non-changeable and non-refundable; however, most low-cost carriers now offer a higher-priced fare with flexible ticket options, including limited refunds and changes to flights.

Please note! Ticket restrictions and conditions may vary from airline to airline. Not all airlines and charter services will operate as described above - contact your airline for further details.

Flight Availability: When searching for long-haul flights - your availability display will indicate several airline options. Often the cheapest deals will involve stops or change of aircraft or both.

When deciding between airlines, remember that 'direct' does not necessarily mean non-stop. On a direct flight, you should not change aircraft, but it may stop to pick up fuel or other passengers - so the journey might be much longer than on a non-stop flight.

Sometimes you will be offered a route that requires a change of aircraft, referred to as a connecting service. If you are offered a reservation on a connecting service, check with the airline or travel agent that you have sufficient time to 'make the connection' between flights. Top Tip: If you prefer the quickest route possible, look out for the flight duration (shown in hrs) displayed next to each flight and select your flight accordingly.

For further information on connecting flights, read our airport faqs section - What to consider when booking flights with a change of aircraft?

If you have any special needs or requirements for which you think an airline might have to make special arrangements, please discuss your requirements as soon as possible direct with the airline or travel agent. You may find your choice of airline will be based on which airline can best meet your particular needs. Airlines sometimes charge for special services, so check before you book. Below are just a few examples of Special Needs for which airlines will need to make arrangements:

• If you are disabled and need help travelling around the airport terminals, on and off the aircraft or moving around inside the cabin.
• Oxygen and or special medical equipment needed during the flight must be advised to the airline well in advance of departure.
• If you are buying a ticket for an unaccompanied minor (you will need to check the age limit and conditions with the airline concerned).
• If you have special dietary needs you should advise the airline when making your reservation.
• If you will be travelling with babies or very young children and you need a sky cot or baby bassinet.

If you are taking a series of flights, ask your airline or travel agent about the baggage allowances for each flight. Allowances between airlines can vary quite a lot, with budget and low-cost airlines having the most restrictions.

Sometimes your baggage allowance will be determined by weight; or the number and size of bags, or it can be a combination of the two. Nowadays, it's best to check the baggage restrictions and conditions directly with the airline before booking your flights.

Make sure your bags are strong and in good condition. For hold luggage, lock the bags and put a strong strap around them. When checking or using the baggage drop at the airport, you will be given a receipt for each bag. The receipts are the sticky labels that the check-in staff usually attach to your boarding pass or passport. Keep these receipts safe, as you may need them if your luggage goes missing and you make a claim.

Baggage security and check-in procedures can be complex and sometimes change at short notice - check with your airline or travel agent for the latest information..

If you have any special dietary requirements, ask if the airline can provide the meal you want before you book. Order any special meal request you may have well in advance of departure.

Some Airlines provide free soft drinks; some provide alcoholic drinks, but check before you book if it's likely to influence your choice of airline. Some airlines do not serve alcohol at all, usually for religious reasons.

Click on Flight4's Destination Guides for tourist and airport transfer information. The F4 Travel Guides will help inform on local transport options, upcoming events, sightseeing, tours and excursions, shopping tips, restaurants, nightlife and much more.

On many routes, the price you pay will depend on when you want to travel. There can be variations in price for different seasons and travel on specific days of the week. In general, airlines offer their lowest fares on days and times with the least demand.

If you can be flexible about your travel plans, you could save quite a bit on your flights. For good deals on flights, hotels and car hire, start searching using one of the many featured ticket suppliers listed on Flight4.com