We will organize this section into overviews on select topics in a sequential order. Here are the topics we are going to cover:
- Recommendations on AmazonÂ
- Recommendation systems, also known as recommender systems or recommendation engines
- Categorizing recommendations, such as:
- Implicit recommendationsÂ
- Explicit recommendationsÂ
- Recommendations for machine learning
- Problem formulation for explicit recommendations—the details
- Weapon sales leads and past sales data—the details
 Each topic will be reviewed with an explanation. We will start with the first topic—Recommendations on Amazon.