What is the difference between require_relative and require in Ruby?

Question

What is the difference between require_relative and require in Ruby?

Answer

Just look at the docs:

require_relative complements the builtin method require by allowing you to load a file that is relative to the file containing the require_relative statement.

For example, if you have unit test classes in the "test" directory, and data for them under the test "test/data" directory, then you might use a line like this in a test case:

require_relative "data/customer_data_1"