Difference between wooden crib and pack and play/playpen?

What's the difference between a wooden crib and the playpen? I cant decide which one to get and i've always liked wooden cribs cos i like wooden furniture but i want to know if there's any safety issues or if the playpen is lighter or easier to move around? If space is an issue to you, which would you go for? My mom didnt like the wooden crib cos she said when the baby starts to bounce or crawl, she's worried baby might hit herself on the wooden surface.. she prefers the playpen that has all soft material.