A traditional bidet is a porcelain bowl that is sat on for the purpose of washing the human genitalia. It's a separate plumbing fixture usually installed beside the toilet. It can be used to wash feet as well, and in several European countries, it's required by law to be present in every bathroom that contains a toilet bowl.
With the advancement of technology, we now have something called an electronic bidet, also known as an electric bidet, bidet seat, bidet toilet seat, or washlet. The electric bidet is a seat that attaches itself to a regular toilet, replacing the existing toilet seat. It usually has a nozzle that sprays a stream of warm water for cleansing the anus and female genitals, and can be controlled electronically. Even with traditional bidets, it used to be associated more for feminine hygiene, but that is far from the truth, especially with all the features an electric bidet has, including things like rear cleaning and a heated seat. The obvious advantages of a electric bidet over a traditional bidet are that the electric bidet is packed full of features, and doesn't need any alteration in the plumbing to be installed and used. In fact, installation for electric bidets are quite easy and a plumber, electrician, or handyman isn't usually needed. Electric bidets just need access to a GFI electrical outlet. In most Canadian households, the outlet is usually placed far away from the toilet, near the sink area. Some people who want a clean look will hire an electrician to make an extra outlet near the toilet. Most people just use an appropriately gauged extension cord instead.