Price to earning reflects the priciness of a share. That is, how many times we are paying with respect to its annual earnings per share. PE of 10 means we are paying 10 times the earning per share to buy the stock. Stock having EPS of 5 and market price of 250 is being traded at PE of 50.
Usually each stock has its own historical PE. Share price of a Company having high business moat and good future demand is always traded at high PE. Asian paints is one of such stock which have historical PE of 50+. This PE is maintained since last 3 years hence historical PE of Asain paint can be considered as 50. Apollo tyre has historical PE of 10.
Stocks should always be bought at average PE levels or better at levels lower than historical PE.