What do individual plan parameters mean?

Each plan comes with the following parameters:

• Credits: These are the units used to measure your API usage. One credit is equivalent to 0.5MB of output data. Therefore, an output file smaller than 0.5MB consumes 1 credit, a file size between 0.5MB and 1MB consumes 2 credits, and so on.
• Rate Limit: This defines the maximum number of conversions you can perform per minute.
• Concurrency: This indicates the maximum number of conversions that can be executed simultaneously.
• Max Delay: The longest period the converter will wait for asynchronous JavaScript operations to complete. This duration is independent of the overall maximum allowed conversion time of 60 seconds.