What is pericarp?

Hint: It is actually a part of the fruit of the angiospermic plant which is also known as the fruit wall. Fruit is found only in members of angiosperms among the entire plant kingdom.

Complete answer:
Generally, the flowering plants or the angiosperms are characterized by the presence of a fruit. After fertilization, the ripened ovary or the mature ovary is called fruit. A fruit mainly consists of the two parts namely the fruit wall and the seed.
In the following question we are concerned with the fruit wall.
Fruit wall or pericarp develops from the wall of the ovary. It can be dry or fleshy. If the pericarp is thick and fleshy then it differentiates into the three different layers they are-
Epicarp (the outer one), Mesocarp (the middle one) and Endocarp (the innermost layer).
Let us understand the nature of fruits through these examples.
In mango and coconut, the fruit is known as drupe. They originally developed from monocarpellary superior ovaries and are usually one seeded. When we talk about Mango, in mango the pericarp that means the fruit wall is well differentiated into out thin epicarp (that means the outer layer is thin), a middle fleshy edible mesocarp (the part we eat that pulp is actually Mesocarp) and an inner stony hard endocarp (In local words we use ghusli term for this endocarp). In coconut the only difference is that the mesocarp is fibrous.

Note: This is to remember that pericarp is the entire fruit wall and the above described epicarp, mesocarp and endocarp are parts of pericarp.
Often, confusion arises between epicarp and pericarp.