AWS glue combining multiple input into a single output csv

Hi , could you please clarify:

1. is it AWS Glue or Glue DataBrew?

2. can you describe better the flow in the Job?

When speaking about combining multiple files and having a single output, there might be multiple methods:

1. joining the input files (if the files have a common key and they want to combine the fields of both files)
2. using a union (if they have the same schema and they just want to append a file to another)

obviously after they have combined the files they will be able to use a single Target node to write out. AWS Glue and Glue DataBrew, are running on top of Spark, so the output even of a single target would be split in multiple files, if they need one single file:

1. in AWS Glue they could just add a step to reduce the number of Spark partitions to 1 using the function coalesce(1)
2. In DataBrew, unless it is recently changed, you do not have this option please check this other question/answer.

hope this helps.