According to the interaction, friends may fall into four categories: bosom friends, good friends, ordinary friends and acquaintances.
As to bosom friend, one is enough. It doesn’t matter what gender he or she is, how long you have known her, how far you are now away from her, and how often you chat with her. You will not tell her anything, but the thing you will tell must be related to your deepest feelings. Besides your parents, she is the one to point out your bad habits which may have bad effects on you, to make you smile whenever you are sad, to talk with you free from any kinds of jokes and topics, and to induce the most genuine things of you. Sometimes she may do everything for you better than your parents. "We will be bosom friends forever" maybe harder than the promise between lovers. There is a saying that bosom friend aren’t those give 10 thousand when she owns 10 billions, but those give you all her money even if she only owns one cent. If you own a bosom friend, you are lucky enough.
Good friends are those stay with you for most of your everyday life, and experience most of your experience. You may have many secret thoughts to share with her and many stupid things to do with her. However, sometimes you may consider the property of the things you are about to talk with her for avoiding offending her, because more or less there will be some benefits exist between you and this type of friends. Maybe that’s why you can’t treat them as your bosom friend. You don’t mean to separate them on purpose, but the only thing you know is that they are different.
Ordinary friends are those work with you as classmates or colleagues. They may help you a lot when you are in trouble, only if the consequence does no harm to them.
Acquaintances are those you have met with but you will hardly have interacts later. But if you come across with each other, more or less you will shake hands, smile, or nod your head and walk away.
The criterion of the classification about friends may be different among people. No matter what type she belongs to in your mind, you should treat them with your enthusiasm, for you will be rewarded with their kindness as well.