Bundle products enables you to sell a group of products with a range of configurations at a discounted price.
In the main menu go to Products and then All Products and select an existing product you want to edit or Add New to add a new product.
In the Product data box at the top you will see a dropdown, by default this will be set to Simple product, but you need to change this to Product bundle.
Now we need to go to the Bundled Products tab and we can change the layout and form location and the grouping (generally you should set this to "Grouped") and also whether you want to enable customers to edit the bundle on the cart page.
Now in the search box, search for the products you want to add to the bundle. As you add each product you will be able to edit basic and advanced settings for the product. This includes whether it is optional, the min and max quantities and whether it is shipped or priced individually.
Of course once you are done press the update/publish button on the product page.