https://www.adrenaline.com.au/files/adventures/slider_images/12778/01.jpg
[SOURCE](https://www.adrenaline.com.au/sydney/skydiving/beach-wollongong-weekday-14000ft-free-transfer/)

According to science skydiving , can be said to be a method  of transiting from a very high point to Earth with the help of gravity, also involving the control of speed during the descent with the use of a parachute . It may as well  involve more or less free-falling which is a period during the parachute has not been deployed and the body gradually accelerates to terminal velocity .
According to sport Skydiving is a sport involving a skydiver to jump down from an airplane while it is flying and parachuting to the ground.
The inventor of the parachute is Leonardo da Vinci. He sketched a “flying tent” as a rescue device for house or tower fires in the late 15th century. the amazing part is  that his device actually works - the material and measurements are all correct.
The first to actually jump with a parachute was Fausto Veranzio. It is widely believed that in 1617, Veranzio, then aged 65 and seriously ill, he implemented his design and tested the parachute by jumping from St Mark's Campanile or from St. Martin’s Cathedral in Bratislava.
The modern round “bell” parachute was later invented in the late 18th century by Louis-Sebastien Lenormand in France, who made the first recorded public jump in 1783. Lenormand also sketched his device beforehand. He also coined the word "parachute" for French “against-fall” describe the aeronautical device's real function. Parachuting was first introduced as a hobby in 1930s in Soviet Union; their intention was to raise paratroopers for army The whole situation changed in the 1970s when the  invention of the wing parachute and the safety culture. Today skydiving is a fairly safe hobby.
Skydiving as we know it today was invented post WWII (World warII). There was a plethora of both surplus gear and surplus aircraft, and many ex-servicemen bought surplus parachutes, light cargo planes and began to jump for leisure. The modern disciplines of the skydiving were invented during the sixties.
Skydiving can be done individually and also with lots of people. Training is required to do it alone. The jump can also be made from a helicopter or the bottom of a hot air balloon or a plane from 4000m or 13,000 ft. Skydiving can be a very exciting in the history of sport.
http://www.hudson.edu/custom_users/mmtech/16926/16926/How_To_files/shapeimage_2.png
[SOURCE](http://www.hudson.edu/custom_users/mmtech/16926/16926/How_To.html)
http://www.hudson.edu/custom_users/mmtech/16926/16926/How_To_files/shapeimage_1.png
[SOURCE](http://www.hudson.edu/custom_users/mmtech/16926/16926/How_To.html)
Skydiving is a highly dangerous activity that needs to be done in a certain and secure way in order to avoid injury. It typically involves a group of people, consisting of a trained, expert diver, and a group of new divers. These people jump out of different aircrafts, the most common being an airplane, but it  can also include helicopters or even hot air balloons. In order to leave the vehicle safely the aircraft needs to be at approximately 4000 meters (12,000 feet). After the person has jumped from the plane, they free-fall for a little then activate their parachute to decrease their falling speed in order to help control the direction they fall, the diver will use cords called “STEERING LINES”, with handgrips called “TOGGLES”. These are necessary to get the parachute to land on the desired safe ground or target. Beginner divers may choose to preform a tandem dive, meaning they are strapped into one parachute to an experience diver. These jumps allow safe control over the new jumper and reduce the fear and anxiety of a first jump. USPA (United States Parachute Association) is an organization that gives training and diving for all levels of skydivers and everyone who is interested to participate in skydive.
with skydiving, as you continue the training and make experience the disturbing anxious feeling bordering to controlled panic gradually let go to the sheer excitement and fun of the freefall. But not quite, no such thing as routine. You feel that you can do more and better, also in the fields where you are generally least confident. Such thoughts might be childish and lacking logical foundations, but no one can take this confidence away from you once you enabled it.
You already knew that it is not something you do just to show off or to tell the tale, there is too much at stake, now you know that you really do not need to tell everyone to be cool: you are already awsome, you did it, fuck their validation. You are nothing but a skydiver.
Tandem skydiving refers to a type of skydiving where a student skydiver is connected to a harness attached to a tandem instructor. The instructor guides the student through the whole jump from exit through freefall, piloting the canopy, and landing. Is extremely safe. The sport has not had any reported casualties in the last 20 years.
https://upload.wikimedia.org/wikipedia/commons/thumb/4/46/Tandem_parachute_and_harness.JPG/260px-Tandem_parachute_and_harness.JPG
[SOURCE](https://en.m.wikipedia.org/wiki/File:Tandem_parachute_and_harness.JPG)
 to be frank skydiving these days is very safe. But make sure you get  attached to a very experienced skydiver like a tandem-master greatly decreases the risk of human error which the cause of the vast majority of skydiving accidents, New jumpers generally start their skydiving career by jumping in the “box position”. In this position the jumper should fall at a rate of 125-mph with their stomach pointing to the earth the whole time.
https://upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Tandemskydive.png/260px-Tandemskydive.png
[SOURCE](https://en.m.wikipedia.org/wiki/File:Tandemskydive.png)
 Next, jumpers need to know when to deploy a parachute at the correct time. This is part of a huge safety issue, making use of  the parachute at the wrong time may end in serious injury or death. The minimum for a practical new jumper would be 2,000 feet. The next challenge for an inexperienced diver would be knowing how to land. A good landing shouldn’t cause the jumper any discomfort at all. The two major keys to landing is focusing and relaxing. Todays experienced divers can land within 2-inches of their desired target.
https://upload.wikimedia.org/wikipedia/commons/4/4e/Ilovechicago.jpg
[SOURCE](https://en.m.wikipedia.org/wiki/File:Ilovechicago.jpg)
At some dropzone tandems are from 3000 m height and shortly after exit the tandemmaster throws out a drogue which is sort of a miniature parachute that slows the jumpers down and stabilizes them. Around 1500 m (I believe) they pull the main chute and enjoy the view for a few minutes before landing :)
*Pros and Cone of skydriving*
PROS
**Bucket list**

**sport/competition**

**it brings a great experience**

**andrenaline rush**

CONS

**It is expensive** 

**it can lead to long term injuries**

**it is time consuming when learning and during training**

**it is dangerous**

The big countries of skydiving are US, UK and Germany. Incidentally they are also the countries which have bring in massed paratroopers in war. For this reason skydiving was heavily subsided and popular in USSR: you could get to jump ridiculously cheap, and cosmonaut Valentina Tereshkova is a skydiver, not pilot. There are plenty of drop zones in Russia even today.

Reference
(https://en.m.wikipedia.org/wiki/Tandem_skydiving)
(https://en.m.wikipedia.org/wiki/Parachuting)
(https://www.quora.com/How-was-skydiving-discovered)