A few weeks ago, I observed that the movement of my car was not as smooth as it used to be. From experience, I knew that at least one of the tires has likely gone bad. Perhaps it's time to change some, or even all of my tires, I thought to myself.
Knowing the economic implication of my thought, I decided to try and save up against the purchase of the tires. Maybe in about 2 months' time, the fund will be ready. Not knowing that the tires had their own plans. Just before getting to my destination that same day, the front tire on the driver's side became so wobbly that I only managed to go the few more meters needed to reach my destination - with the hazard light on.
I parked, brought out the jack and wheel spanner, jack up the car from the front tire driver side to see that the tire has has been eroded in the inner side up to the point that the binding wires are beginning to show up. In order words, the tire has been condemned beyond use. From the outside, the tire looked great. What could have happened that tires will be eroding on one side? I was convinced it is an alignment issue.

I called my mechanic just to confirm with him if my presumptive diagnosis was right. He was sure that even though the tires might need alignment, the current issue is beyond just alignment. The arms of the car need checking. Since I was not feeling so great around that period, I told him to come and take it to the workshop for checking a few days after.
He confirmed that the low arm bushings needed replacement, after which alignment for the tires was recommended. He also confirmed that, at least, two of the tires must be replaced. I sent him money to get new low-arm bushings and asked him to do the alignment before bringing it back home. He brought the car back in the evening of the same day. I regained my strength a few days after and decided to go out and get fairly used tires as new ones are quite expensive.
When is alignment necessary?
When I started driving, I learned that alignment is necessary whenever a major fault is corrected on the arms of cars. When driving on a smooth road, a car that lacks alignment issues should continue on a straight line even without holding the steering. Once a car starts pulling to the left or to the right without any hindrance to the tires, such a car requires alignment.
Beyond my initial knowledge, wheel alignment is recommended for cars that usually travel through bumpy roads or roads littered with potholes. Even when the usual roads plied by a car are smooth, wheel alignment is routinely recommended between 2 to 3 years intervals, when tires are replaced, or when a car enters into an accident.

Well-aligned tires will make for a smooth driving experience, prolongs the lives of the tires as the uneven wearing of tires is one of the symptoms of bad alignment, make the suspension system last longer, and reduce the likelihood of tire blowouts while on the road.
Basically, aligning a car has to do checking and adjusting the angles that the car's suspensions make with themselves and the body of the car itself. Three attributes of the suspension system are checked - the camber, the toe, and the caster.
When is wheel balancing necessary?
Wheel balancing refers to balancing the weight of wheels in relation to the tires. This is done using a precision machine and as pointed out in the definition, when tires are placed on wheels. In other words, wheel balancing is necessary only when the tires of a car are replaced.
The balancing is necessary because of the uneven weight distribution of the wheel. That is, the default production condition of wheels is such that some parts are thicker while others are lighter. The wheel/tire combination is placed on the precision machine, rolled, and the light side of the wheel is detected through the oscillation of the tire. A small metal that usually comes with wheels is then attached to the light side to balance the entire structure.
From experience, once the car speedometer goes above 80 km/hr and vibration sets in, I know that the wheels of the car need balancing. The speed threshold might vary from car to car, however.

Around here, wheel alignment technicians are quite common, unlike wheel balancing technicians. This could, perhaps, be due to the cost of the precision machine or the technical know-how. In my own case, I took the long trip to a technician that has knowledge of the two.
The first thing he did was to remove all the four tires and balance their weights with their wheels one after the other. Thereafter, the car was driven onto a ramp where the alignment was done. The entire process took less than 30 minutes.
Summary
Wheel alignment and balancing of cars are necessary for a smooth driving experience. In addition, aligned wheels will prolong the lives of tires and the suspension system of cars as well as reduce the probability of having tire blowout.
Thank you all for reading.
Resources
https://www.supaquick.com/blog/the-importance-of-wheel-balancing-andalignment-for-safe-driving
https://www.ceat.com/blog/car-tyres/get-to-know-your-car-how-often-should-wheel-alignments-be-done.html.