There are various ways to open a padlock. Best variant: use a key. If you don’t have any, use a lock pick (needs some training and the right tool for the right lock). If you don’t have any, use a bolt cutter or battery powered cutter, but the lock then is visibly destroyed.
There’s a few more methods that are not very well known. All of them will be shown on our page with videos, different lock types, different tools, different ways to open a lock and the pros and cons.