What is trekking ? Discuss various types of trekking.

Trekking refers to travel by foot through remote destinations that are in most cases inaccessible and unknown to visitors.Trekking is mainly of four kinds:
1 Easy Trekking: This type of activity if for beginners and basically involves the view of colorful horizons or sight of beautiful nature. 
2 Moderate Trekking: Moderate trekking is more challenging than easy trekking. It is performed on medium to slightly higher altitudes. The individuals doing this type of trekking should be energetic.
3 Strenuous Trekking: This type of trekking requires strenuous physical efforts. It is basically done on high altitude regions and is suitable only for those who have some previous experience of trekking. 
4 Difficult Trekking: Fourth type of trekking is done on steep slopes. Generally professional or experienced trekkers do this type of trekking. This type of trekking requires high level of precision skill and endurance by the trekker.