It definitely is mother's love. The second a women knows she is going to become a mother, she starts thinking about the child. She becomes the guardian angel to the child. Pains due to pregnancy makes her happy as she will get a sweet child in her hand. She struggles a lot but the thought of the child her mind screams in happiness. Children may be good to her or neglect her but she never stops caring for them nor does stop praying for their happiness. Even if they leave her alone and moves far, she wishes for them to be successful and happy where ever they are. The love and care of a mother starts when she knows that she is pregnant and it continues even beyond her death in form of blessing. Many children do love the mother as much as she does, but this love comes after they see her and feel her love. Whereas mother starts loving the child even before seeing or feeling them. A very true and precious love. The greatest treasure to children. The sad part is some don't realise until they loose it.
Both have their own ways of showing love. Without mother's love, there is no child. Without a loving child, there is no sense of satisfaction in motherhood. P.S : The above lines are in a general perspective. There are exceptions to everything.
Mother's love. Except when it the mother is a mother-in-law, then apparently her love for her son is ahem .. cochenable