What is "love" to a lay person?
Love is a very overloaded term. There are many different phenomena that fall under the umbrella label of "love":


There is love as obsessive kama (liking/desire) towards someone or something. This should probably be classified as lobha (greed, obsessive desire).
There is non-reciprocated love, longing for something you can't get. This is probably tanha (unsatisfied thirst, craving) - the root of dukkha.
There is love towards your mother, family, friends, town, country. This could be pure metta (loving-kindness) or metta with attachment. The first is a wholesome kind of love, producer of good karma. The second subtype, love with attachment, will serve as the root of dukkha once the impermanence kicks in.
There is love of self. This can be an egoistic form of love, or a kind of acceptance/appreciation - a factor of healing.
There is love as unconditional acceptance/appreciation of someone or everyone and everything -- a non-dual kind of love that does not draw lines between "self" and "other". In my understanding, such love is a factor of Enlightenment.


Summarizing the above, there seems to be two main types of love: attachment-type and acceptance/appreciation-type. The first type is a factor of dukkha, the second type is a factor of good karma, healing, Enlightenment.