What is the meaning of eg?

"Eg" is an abbreviation for "for example". It's used to introduce one or more examples that illustrate a point you're making.

Example:

"Many fruits are good sources of vitamins. Eg, oranges are high in vitamin C, and bananas are rich in potassium."

Here, "eg" introduces the examples of oranges and bananas to illustrate the point about fruits being good sources of vitamins.