The following storage classes are available in Amazon S3:
S3 Standard- It is by and large the default storage class. In cases where no specification about the storage class is provided while uploading the object, Amazon S3 assigns the S3 Standard storage class by default.
Reduced Redundancy- It is assigned when non-critical, reproducible data needs to be stored. The Reduced Redundancy Storage class is designed in a way that the above data categories can be stored with less redundancy.
However, it is always advisable to go ahead with the S3 Standard storage class.