I had a German friend who once told me that there are many words for love while in English, there is only one word, love. Can you tell me what she meant?
People who learn a foreign language often only learn a small part of it compared to the whole language. This leads them to conclusions like:
My language is complex and adaptable but your language is rigid and basic.
They might also think what your friend thought; they knew a dozen different German words for love (because it's their native language), but only one in English. This led them to the false conclusion that German must have more words for love over all.
to love can be used in many contexts while lieben cannot. Both mean a very strong positive emotion that leads to a kind of inner bonding (that can be unilateral). The use of lieben is generally restricted to persons or pets if one's talking about them, but only to partners in love if one's talking to them.
I love my husband. - Ich liebe meinen Mann.
I love you, darling. - Ich liebe dich, Schatz.
I love my father. - Ich liebe meinen Vater. / Ich mag ihn sehr. / Ich habe ihn sehr lieb.
I love you, dad. - Ich habe dich lieb, Papa.
She loves her dog. - Sie liebt den Hund / Sie hängt sehr an dem Hund.
I love you, Fido. - Ich habe dich lieb, Fido.
I love playing soccer. - Ich spiele sehr gerne Fußball.
I love pizza. - Ich mag Pizza sehr gerne. / Ich stehe auf Pizza.
Note: Usage is changing right now. That might be due to the big influence English has on German at the moment. You can hear i.e. Ich liebe Pizza more and more frequently.