As defined on wikipedia.
Friendship is co-operative and supportive behavior between two or more people. In this sense, the term connotes a relationship which involves mutual knowledge, esteem, and affection and respect along with a degree of rendering service to friends in times of need or crisis. Friends will welcome each other's company and exhibit loyalty towards each other, often to the point of altruism. Their tastes will usually be similar and may converge, and they will share enjoyable activities. They will also engage in mutually helping behavior, such as exchange of advice and the sharing of hardship. A friend is someone who may often demonstrate reciprocating and reflective behaviors. Yet for many, friendship is nothing more than the trust that someone or something will not harm them.
I like the words that have already been highlighted for me (they're links to other definitions).
That sure is not a lot to ask. Not when you get strawberry cupcakes and giggles in return.