In "Politics and the English Language," George Orwell, a beautiful English prose stylist, presents a set of six rules. One is "(iv) Never use the passive where you can use the active." Use the active voice if you can. Use the active voice when you want to be clear and direct, and sound vigorous. The passive voice puts emphasis on what was done instead of who did it, which sometimes can be appropriate. For example, "Make sure all the books are put away," because you don't care who does it as long as it gets done. The passive voice may be appropriate when the person who performed the action isn't known: "My car was stolen." (Passive voice) "Somebody stole my car." (Active voice) The passive voice is a favorite with people who do not want to be clear, direct, or vigorous. It can be used to evade responsibility; instead of "I made mistakes," one can say "Mistakes were made." The passive voice is common in "administrativese," and in formal scientific writing.

A sentence in passive voice means the action happens to the subject. The subject receives the action. A sentence in active voice (this is a "regular" sentence) means the subject performs the action.

For my opinion you don't have to care about which voice you must use between them. That always depends on the situation. There is no rule anymore in the use of active or passive voice when writing or speaking. Image that you have two young brothers Paul and Joe that don't get along. They always fight. Image that Paul put his book on your living room table and then Joe took it when he wasn't there. What would you have answered if Paul asked you: 'Where's my book, sister?' You could tell him who took his book in two manners. 1. Joe took your book. (active) 2. Your book was taken by Joe. (passive) If you considered the question you should have used the second one. It's better to begin with the main word(s) when speaking or writing in any language. Paul asked you a question about his book, so the main word was "book". Image now they fought because of that. What would you have reported to your mother to stop them? You should have said "Joe took Paul's book and they're fighting" and not "Paul's book was taken by Joe and they're fighting". But you could say "It was taken by Joe" if your mom asked about the book. In English, there are also some sentences that are always in the passive voice. Example: I was born in Senegal. No one can give life to himself. If you want to know how to make a passive voice from a sentence in the active voice, here's the rule: 1. the object of the sentence in the active voice is the subject of the sentence in the passive voice. 2. the subject of the sentence in the active voice is the object of the sentence in the passive voice. 3. the verb in the passive voice is made by putting the auxiliary "to be" in the tense that is the main verb in the active voice with the past participle of that verb. Example: The police had caught the robbers. (active, past perfect) The robbers had been caught. (passive, be in the past perfect + past participle of "to catch")