More about catheters:
There are two main types of catheter:
Intermittent - these are often called in/out, nelaton or Robinson catheters and are inserted into the bladder just to allow it to be emptied and are then removed
Indwelling - or Foley catheters are designed to remain in the bladder for a continuous period of time. They can either be inserted into the bladder via the urethra, in which case they are called urethral catheters. Sometimes it is necessary to insert the catheter via the abdomen (during a small surgical procedure) in which case they are called supra-pubic