how do bases show basic charecter?

According to Arhenius concept of base if a substance release OH^- in water then it is said to be a base. So this concept cannot be used for the bases which donotdis consider this concept in the case of bases that donot have (OH)group or which donot dissolve in water.In those cases we consider Lewis concept and Bronsted-Lowry concept.

According to Lewis  concept if a substance donates electrons then it is said to be a base for example:Et₃N

Bronstead base is a substance that  accepts H⁺ ions for example NH₃