That depends first and foremost on what type of person you are and what demands you place on a watch. The following table shows you a few constellations of type and watch.
Different models and the type that goes with them
Type
Clock
classic type
Automatic watch with leather strap
sporty noble type
Pilot watch with steel bracelet
fashionable type
eye-catching watches as an eye-catcher
casual guy
sporty smartwatches with high functionality, digital watches
nostalgic type
classic quartz watch in antique style

Regardless of whether it's a ladies' or men's watch, it shouldn't be too big, because that always looks very ostentatious. Especially if you have a very narrow wrist, you should pay attention to the right size of your chronograph.
You can use the 18 to 40 rule for this. This rule states that a wrist with a maximum circumference of 18 centimeters should never wear a watch with a diameter larger than 40 millimeters.

Basically, you can divide the material of watches into three categories: Plastic glass, mineral glass and sapphire glass.
Plastic glasses are made of polymethyl methacrylate and the common names are plexiglass, acrylic glass and hesalite glass. This material is very light, relatively impact resistant and you can polish it easily. However, it scratches quite quickly. Scratches can be repaired by polishing.
Mineral glasses have a higher scratch resistance and a higher degree of hardness, but they can still be scratched. If this is the case, they cannot be polished away as easily as with plastic lenses.
Sapphire lenses are especially convincing due to their enormous scratch resistance as well as their durability. If you do notice traces on the glass, these are usually not scratches, but residues that other materials have left on the sapphire glass. You can easily remove these with an eraser.
However, sapphire crystal also has a disadvantage: light refractions often cause unfavorable reflections.

Watch movements are divided into four categories: Hand-wound movement, automatic movement, quartz movement and radio-controlled movement.
A hand-wound movement is usually found in older watches. It is the true classic among the movements and convinces through sophisticated technology and historical significance. However, hand-wound watches have one major disadvantage: they run out of power after about two days. If you do not wind the watch in time, the movement stops and you have to reset it.
A hand-wound movement always consists of three components: Gear train (gears), drive and escapement. To start such a mechanical watch, you have to turn the crown on the watch case. The torque is transmitted to the spring movement and from there, with the help of the gears, to the escapement wheel. The exact torque is transmitted to the balance wheel. The balance is the oscillating system and serves as the rate regulator. It always oscillates back and forth, always with the same time interval. These oscillations are transmitted to the gears on which the second, minute and hour hands are mounted.
An automatic movement winds itself by the movement of your arm. To do this, they are equipped with a ball-bearing rotor. This stops due to the inertia in space as soon as you move the watch case. The resulting forces exert a torque on the winding mechanism and the watch virtually sets itself.
The quartz movement has so-called bending oscillators in rod form, which represent a vibrating unit and allow higher oscillations to achieve better accuracy. The unit usually gets its oscillations from a battery, or from a mains connection if it is a large wall clock. A built-in coil passes the current to an oscillator, which sets the bending oscillator in motion. This drive requires very little energy, which is why quartz movements run very efficiently and remain operational for years with just one battery.
The bottom line is that the operating principle of a radio-controlled movement has not changed since the 1970s. In most countries of the world, transmitters have been installed which emit an accurate time signal. A radio-controlled movement intercepts this signal and forwards it directly to your watch.

A wristwatch is considered water-resistant when it can withstand at least five bar of water pressure. Five bar corresponds to approximately 50 meters. However, this does not mean that you can dive 50 meters with such a watch. With a watch that can withstand five bar of water pressure, you can at most wash your hands.
Water pressure in bar for water resistance
Bar
suitable for
3 bar
splash-proof
never take a shower with it, let alone go swimming
small splashes of water are no problem
5 bar
Suitable for hand washing
10 bar
Suitable for showering or swimming
20 bar
you can use for diving
Suitable for all water activities

The best way to clean your watch is with clear water and a dust- and lint-free cloth. If this does not help, use a little washing-up liquid. This is usually fat-dissolving and does not attack the material of your watch.
Under no circumstances should you use aggressive cleaners such as bathroom cleaners or similar. Wristwatches are usually coated and suffer from aggressive cleaning agents. The material becomes dull and loses its shine.

You can change the bracelet on any watch, but it depends on your skills.
The most important thing is that the new bracelet has exactly the same width as the old one.

As a rule, wristwatches are either equipped with a pressure caseback or with a screwed watch case.
You can recognise a pressure case back by a small indentation, which you can best open with a pointed object. If you push it under the notch, you can easily lift the pressure case back.
If the watch case is screwed down, you will usually have to use a special watch tool to get it open.
Once you have opened the watch, you can simply remove the battery and insert a new one. I advise you to use tweezers to change the battery. Otherwise you might destroy important parts of the movement.

This varies from child to child and usually depends on the learning ability of the offspring as well as the upbringing of the parents. As a rule, however, children become interested in a watch all by themselves at some point and want to be able to read it even before they start school.
The perfect age for a children's watch is therefore pre-school age. From this age onwards, you can try to integrate clock reading into everyday life in a playful way. A child's alarm clock can help here by pointing to the hands and explaining the position each time before going to bed.
Furthermore, preschool age is a good time, as children at this age need to slowly get used to time sequences.

Smartwatches have functions that are equivalent to a smartphone. Internet access, telephony, SMS or Whatsapp are not uncommon with these watches. Moreover, you can also enjoy the full range of audio and video playback with a smartwatch. For this purpose, they are usually equipped with a built-in sim card or you connect the watch via Bluetooth with your smartphone.
In addition, smartwatches usually offer even more functions that are very helpful, especially in the sporting field. For example, you can do sports with them and they show your heart rate, running distance, speed and other important information.