What is the meaning of unconditional love?

what is the meaning of unconditional love? my husband have kids to her ex wife.. i am a filipina his 2 kids live with us.. i want to know what is the meaning of unconditional love..what is the different between the love of my husband to his kids and lso the love of my husband to me.. my husband is a black american.. can u explain to me pls. thank you