Explanation:
Synthetic fibres are human-made fibres that are produced by polymerization of different types of chemicals. These fibres are made of polymers, which are large molecules made by joining together many smaller molecules called monomers.

Examples of synthetic fibres include polyester, nylon, acrylic, and rayon. These fibres are widely used in the textile industry for making different types of clothing, carpets, and other household items.

Polymerization is the process of joining monomers together to form polymers. The monomers used in the production of synthetic fibres are derived from petrochemicals. They are heated and mixed with different chemicals to create polymers that can be spun into fibres.

Advantages of synthetic fibres:
- They are strong and durable.
- They do not absorb moisture easily, which makes them good for outdoor clothing.
- They are easy to clean and maintain.
- They can be made into a variety of textures and styles.

Disadvantages of synthetic fibres:
- They are not biodegradable and take a long time to decompose.
- They can be harmful to the environment and human health during the production process.
- They are not as breathable as natural fibres, which can make them uncomfortable to wear in hot weather.
- They can melt or burn easily, which can be dangerous in certain situations.

In conclusion, synthetic fibres are human-made fibres produced by polymerization of different types of chemicals. They are widely used in the textile industry due to their strength, durability, and versatility. However, they also have some disadvantages, including environmental and health concerns.