Thank you for your question, JS.
The Pharisees and the Sadducees were two different sects among the Israelites. Both adhered to the law of Moses and also accepted the other written Scriptures as the Word of God. The Pharisees also had a set of oral traditions and laws that they proclaimed to also be the Word of God. The Sadducees rejected these oral traditions and laws. Thus, the Pharisees were the more legalistic of the two groups.
The Pharisees believed in angels as well as evil spirit beings. The Sadducees believed in neither. The Pharisees believed in life after death.
The Sadducees did not. [That's why they were so "sad-you-see." ]
Both opposed Jesus, though the Gospel records of the Pharisees doing so are more frequent.
Bless.