General Purpose SSD (gp2) EBS Volume - Ratio of 3 IOPS per GB upto 10,000 IOPS. Burst upto 3000 IOPS for volumes under 1GB.
Provisioned IOPS SSD (io1) EBS Volume - For more than 10,000 IOPS. Upto 20,000 IOPS per volume.
Amazon CloudWatch is a monitoring service for AWS cloud resources and the applications you run on AWS. You can use CloudWatch to gain system-wide info on resource utilization, application performance, and operational health, collect and track metrics, collect and monitor log files, set alarms, and automatically react to changes in your AWS resources.
These are only the defaults. Many of these can be changed by contacting AWS or other ways. Refer to the reference link for details.
Flow logs per single network interface, single subnet, or single VPC in a region = 2
VPCs per region = 5