Well, firstly it is a made-up word referring to travel overland, made into a verb by adding 'ing'.
Leaving that aside, overlanding, in my humble opinion, (is that now known as imho?) is a form of tourism.
The truck driver who drives her load from London to Istanbul is not overlanding, but is however traveling overland.
Overlanding is tourism with added adventure, excitement, thrills, and adrenaline. It is not without risk, and occasionally has unfortunate consequences.
Organized trips
The organized trips, such as those by Encounter Overland and Exodus, try to create an atmosphere of exploration and expedition, which I think they generally do reasonably well, but it is not real exploration as the routes are well known to the companies and drivers. Even the out of the way places, have already been reconnoitered by the company.
Please don't think I am in any way trying to put down the companies or drivers. The routes they offer are frequently well away from the beaten tourist routes and it is a far cry from the quick trip down to the Costa del Brit.
All I am trying to say is that it is not the full Monty expedition where you set out in the morning truly not knowing where you will get to nor what you will encounter on the way.
So, back to tourism. It is an adventure. You go to places you may have never dreamed of. See things you will remember for the rest of your life.
But the experience! The experience has the potential of being mind blowing superb. The external experience will be, but can be affected by your fellow travellers. The internal experience comes down to the group you are travelling with in the end. A good driver / leader can influence the group to an extent, and provide the environment for exceptional team interaction and bonding. A good group, with a good driver, and a good company (yes, in that order) has the potential to be a trip of a lifetime. It will be written up in the company's in-house magazine, and told to children and grand-children for years to come. Conversely, a group, that, for whatever reason, will not gel, will not get on with each other, forms cliques, and plays politics, will get significantly less out of their trip, irrespective of driver or company.
Sometimes, with a very good group, a driver may try to vary the route from that normally taken. Whilst on my first trip to Asia, we were approached by a overland driver in Herat. He wanted to drive through the centre of Afghanistan, over the mountain passes, through the Hindu Kush. This is a much shorter route than the southern route via the Desert of Death and Kandahar. It is also, by repute (at the time) much more difficult. A lot of the route is reduced to single lane dirt tracks with no truck size traffic. Donkeys would be a more normal sight. The drops off the side of the road, splendid, and scary. He was looking to maximize his groups experience, with added adventure in the bucket load, whist trying to mitigate some of the risk, by having another truck accompany him.
Just a quick reminder, as we have become so accustomed to our instant world, there were no mobile phones, or any other form or portable communication available to either the driver or us. You were on your own, and if something tragic happened, help was at the end of a long donkey ride.
I must admit that it was a very attractive proposition. However, our truck was only two wheel drive, with standard suspension and had a longer wheelbase than his truck. It also had rigid sides.
Do I hear a "What difference does all that make?" It means that whereas his truck may have been able to navigate the mountain passes, we were less likely so to do. With the added possibility of projecting rocks ripping the side off truck. He had soft sides, and people watching.
The people you travel with make the difference. After all, you are living with them, in close quarters, all day, every day. (24/7). That is more intense than most married couples. They were strangers at the beginning of the trip, and a few weeks in and you are sharing a mixed bath with them! Inhibitions dissipate quickly when you are overlanding, by necessity.
There is often a degree of hardship as well. Tents, rough camping, creepy crawlies, dirt, dust, and more dirt. The food is different, the shops are different, in fact most things are different. And you have to get on with each other, and act as a single coherent team.
Independent Trips
Independent overlanding is somewhat different again. I will only deal here with trips with your own transport, as this is where the majority of my experience of overlanding lies.
In all probability, you know the core team before you set off on the trip. However, this is not a guarantee of compatibility because the same people issues due to intensity and proximity apply. Team interaction is just as important. The really big difference with the self organized independent trip, is if you pick up a passenger along the way that does not fit in, you just say goodbye. Problem resolved.
It is still all about the people.
Enough of trying to give a flavour and explanation of 'What is Overlanding' Read the stories and get the inside info.