What does a line of code mean?

Question

Software testing

What does a line of code from the RoR book mean?
If so, then the test passes without error:

assert_equal ["must be greater than or equal to 0.01"]

And if you change at least one letter, then the test fails:

assert_equal ["must be greater than or equal too 0.01"]

Test result:

[email protected] ~/Dev/depot $ rake test
Run options: --seed 2627
# Running:
..........F.........
Finished in 0.556599s, 35.9325 runs/s, 88.0347 assertions/s.
  1) Failure:
ProductTest#test_Цена_продукта_должна_быть_правильной [/home/beerdy/Dev/depot/test/models/product_test.rb:25]:
--- expected
+++ actual
@@ -1 +1 @@
-["must be greater than or equal too 0.01"]
+["must be greater than or equal to 0.01"]
20 runs, 49 assertions, 1 failures, 0 errors, 0 skips

Answer 1

assert_equal ["must be greater than or equal to 0.01"]

checks that an error is displayed that says must be greater than or equal to 0.01

Answer 2

I understand that this validation, in case of an error, raises an exception in the form of a string:
And this assert_equal method, as I understand it, just compares two strings? It turns out that it is simply used for aesthetic design in tests (or whatever it is called)?