Ionic bonding

ionic bond is that a metal atom lose electron(s) and then have positive charge and also gain a octet structure (8 electron in outermost electron shell), that is called cation now
and there is another atom which gain electron(s) to gain the octet structure, also become negative charged, that is called anion now
at that time, these two type of ion with opposite charge will attract each other by the electrostatic force, and this attractive force is called ionic bood.