Answer
These compounds are diastereomers.
Work Step by Step
If we exchange wedges and dashes on the first structure, we will get a structure similar to the second one, but with some differences: 3 groups will look exactly the same, but 2 of them will be different.
You can also analyze each stereocenter, and you will see that these 3 groups have opposite configurations, but the other 2 will be the same.
Structures with these relations are called diastereomers.
