If your device is labelled ‘water-repellent’, or if it has a water-repellent coating, it will have some protection against water damage.
Devices labelled as water-repellent tend to have a hydrophobic thin-film nanotechnology coating, which repels water. This means they might be able to cope with rain, sweat or the odd splash of freshwater, but they may stop working if submerged in water or if they're exposed to any other liquid.
How is water-repellent different to water resistant?
A water-repellent device won’t have gained an official IP water resistance rating, which is awarded to devices that have passed vigorous water and dust resistance testing.
Phones are generally given an IP rating such as IP68 or IP67 to define how well they respond to water, including being submerged in water of different depths for a set duration of time.
If you’re worried your device may end up being submerged in water, you might want to look at a smartphone with a water-resistant IP rating for peace of mind.