Deposits on house foundation

[GuggeGrön]

Hello
I live in a townhouse and have a concrete foundation, slab on grade.
I have white deposits in an uneven line along the entire foundation. My neighbor doesn't have anything similar.

- does anyone know what it is
- how do you get rid of it
- how do you avoid recurrence?

 

[Stefan N]

Moisture migration causing salt efflorescence.
It probably wasn’t an issue before someone decided to lay stones next to the house.

 

[GuggeGrön]

Moisture migration that causes efflorescence.
There probably weren't any issues until someone decided to lay stones next to the house.

Thank you!
How does the moisture migrate?
Can anything be done to stop it?