A bidet is a type of bathroom fixture intended to enhance personal cleanliness. Typically accompanying toilets, bidets provide a stream of water that you can use to wash your privates after visiting the washroom. They can be installed as stand-alone fixtures, or combined with your toilet. As standalone fixtures, they typically consist only of knobs for releasing hot or cold water, and a spout for the stream of water to come out. When combined with a toilet, they usually present as a nozzle that is independently controlled with knobs that are mounted on the toilet tank, wall or nearby sink.
While a stand-alone bidet certainly adds charm and appeal to any bathroom, installing one can be an involved and costly proposition, largely because you will have to insert plumbing pipes to deliver water to the fixture. You will also have to provide a means for the waste water to be drained away, which may require additional sewage piping installations. This often involves major reworking of your existing plumbing structures, which can cost thousands of dollars and require you to hire a professional contractor.
Bidets that attach to your toilet are much easier and less expensive to install, but also sacrifice some control and functionality. At their simplest, attached bidets run only a stream of cold water, which can be uncomfortable at first, but you can also get more intricate units that allow for warm and hot water delivery as well.
If you are going to install a bidet on your own, make sure you follow the installation instructions and conform to manufacturer specifications exactly. Otherwise, you risk damaging your toilet and plumbing, which can lead to an enormous repair bill that may even exceed the price you'd have paid to hire a professional in the first place.