Active participle is just the 3-letter root with added suffix denoting the number and person:
Sometimes in singular feminine it has the suffix ה instead of ת.
Participles are used like adjectives but may have an direct or indirect object like a verb.
Note that participles have no tense and may denote an action in past, present, or future.
Passive participle is the three-letter root with a letter ו added between the 2nd and the 3rd letter.
A passive participle most often denotes an accomplished action (but it maybe any of past, present, or future).