Following are the benefits of using modules in Terraform :

• Organization of CONFIGURATION: By grouping relevant portions of your configuration together, modules make it easier to access, understand, and change your configuration. Hundreds or thousands of lines of configuration can be required to establish even MODERATELY complicated infrastructure. You can organise your configuration into logical components by utilising modules.
• Encapsulation of configuration: Another advantage of modules is that they ALLOW you to separate configuration into logical components. Encapsulation can help you avoid unforeseen consequences, such as a change to one element of your configuration causing changes to other infrastructure, and it can also help you avoid basic mistakes like naming two resources with the same name.
• Maintains consistency and ensures best practices: Modules can also help you maintain uniformity in your configurations. Consistency not only makes complex configurations easier to grasp, but it also ensures that best practices are followed in all of your settings. Cloud PROVIDERS, for example, offer a variety of options for establishing object storage services like Amazon S3 or Google Cloud Storage buckets. Many high-profile security problems have occurred as a result of IMPROPERLY secured object storage, and given the number of sophisticated configuration options involved, it's possible to misconfigure these services by accident.
• Modules can aid in the reduction of errors: For example, you might design a module to define how all of your organization's public website buckets would be set, as well as a separate module for private logging buckets. In addition, if a configuration for a particular resource type needs to be altered, using modules allows you to do it in one place and have it applied to all scenarios where that module is used.
• Aids in reusability: Setting up the configurations from scratch and writing all of your settings can be time-consuming and error-prone. By reusing configuration generated by yourself, other members of your team, or other Terraform practitioners who have published modules for you to utilise, you can save time and avoid costly errors. You can also share modules you've produced with your colleagues or the broader public, allowing them to profit from your efforts.