What a drip does that a bottle of water cannot
An intravenous drip is a bypass. When you drink water, it has to pass through your stomach and small intestine before it reaches your bloodstream, and that route has a speed limit — roughly a litre an hour under good conditions, much less if you are nauseous or vomiting. An IV skips the queue entirely: fluid goes straight into a vein, so absorption is effectively 100 per cent and immediate. That is the entire trick. There is no exotic technology involved, just a sterile bag of fluid, a length of tubing, a small plastic cannula, and gravity or a flow regulator.
Here is the honest part: for a healthy adult who is mildly dehydrated and can keep fluids down, oral rehydration works nearly as well and costs a few dirhams at any pharmacy. IV therapy earns its keep when the gut route is compromised — vomiting, severe nausea, heat exhaustion — or when someone wants rapid rehydration with electrolytes after significant fluid loss. A good provider will tell you this. A provider who insists a drip is always superior to drinking is selling, not advising.