system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are there places where the desert meets the ocean, like in Saudi Arabia?

I don't understand how you can have a dry sandy landscape right next to an ocean and not have any precipitation and vegetation.
gpt
You need two things for rain - moist air, and a reason for it to fall out of the sky.

If the prevailing wind always blows from the land to the sea in that location, then it's quite likely that the air will be very dry - so no rain there.

If the wind is blowing onto the land from the sea it's possible it's not been passing over the sea for long enough to collect significant moisture, or more likely there's no reason for it to fall as rain. If the airstream isn't deflected upwards by mountains, for example, then it may just move inland as warm moist air until it either rises, or cools, either of which can cause rain.