There are several painting techniques out there. These can be water-based processes such as watercolour, acrylic, gouache, ink, tempera and oil-based approaches like oil paint, and others with a different base like wax for example.
Watercolour techniques
Watercolour is a technique using pigments ground with gummed water. It is usually done on thick paper support. Once the latter is dry, the transparency of the watercolour becomes perceptible. It can also be used on silk. The advantages of this technique lie in the speed of execution and the small amount of material required. It is often used to create comic strips, pochades, study paintings, etc. Watercolour can be presented in different forms: pencils, tubes, cups, chalks, liquid, etc.
Gouache is also a gummed water paint. It is called "tempera paint" too and is simply mixed with other water-soluble dyes or mediums. It can be used again, even when dried, if mixed with water and is easy to clean, although it is usually opaque. Unlike watercolour, gouache is perfect for beginners and even for children's first paintings. It can also be used on different surfaces such as wood, glass, etc.
Acrylic paint is a painting technique using pigments that are mixed with synthetic resins. It is easily diluted with water and its mixtures are easy to prepare and apply. Unlike oil paint, the drying time of acrylic is very fast. But you can always start with acrylic paint and finish with oil paint (the reverse is impossible). You can mix it with other materials such as sand or earth for example...
Oil-based techniques
Oil painting is a technique based on pigments and drying oil. The supports that can be used are mainly cardboard and wood. Various thinners and painting mediums can be utilized to modify its texture or facilitate its application. With oil paint, you can obtain material or elevation effects as it is more water resistant than gouache, which makes it ideal if you like to take the time to mix the colours and rework the motifs over several days.
There are as many techniques as there are supports!
There are also wax-based painting techniques, such as cerra-colla or encaustic paint. Beeswax is mainly used as a binder and is operated on hot surfaces such as canvas, wood, stone and plaster. There are also dry and oil pastels that allow pencil-like strokes, with which one can draw as well as paint.