Attempt is the act of trying to commit a crime but failing in the end. This is because an attempt can involve a commitment to serious crimes like murder, which is considered one of the most serious inchoate crimes.
The act of conspiracy occurs when there are two or more individuals who agree to commit a crime together. Due to this, the act of conspiracy requires two or more participants.
Aiding and abetting is an inchoate crime that is applicable to individuals who are usually not present while committing the crime. This means someone who is aiding or abetting is helping the other person commit the crime either before or after the fact.