EC2

Q1. Difference between dedicated host and dedicated instance in EC2 purchasing option.

Parameters	Dedicated Host	Dedicated Instance
Definition	An Amazon EC2 Dedicated Host is a physical server with EC2 instance capacity fully dedicated to your use. Dedicated Hosts allow you to use your existing per-socket, per-core, or per-VM software licenses, including Windows Server, Microsoft SQL Server, SUSE, and Linux Enterprise Server	Dedicated Instances are EC2 instances that run on hardware that's dedicated to a single customer. Dedicated Instances that belong to different AWS accounts are physically isolated at a hardware level, even if those accounts are linked to a single payer account. However, Dedicated Instances might share hardware with other instances from the same AWS account that are not Dedicated Instance
Billing	Per-host billing	Per-instance billing
Visibility of sockets, cores, and host ID	Provides visibility of the number of sockets and physical cores	No visibility
Automatic instance recovery	Supported	Supported
Host and instance affinity	Allows you to consistently deploy your instances to the same physical server over time	Not supported
Capacity Reservations	Not supported	Supported

Q2. Difference between EBS and EFS

Parameters	EBS	EFS
Definition	Elastic Block Store, network attached volumes	Network file system
Multi-attach	Can attach to single EC2 instance at a time, except io1/io2 volume types (16 EC2 instances at a time)	Can attach to any number of EC2 instances
Scope	Restricted to AZ level	Not restricted at AZ level
IOPS	Increases as disk size increase except io1, for which IOPS can be increased independently	IOPS is independent of disk space
Migration	Take a snapshot in one AZ and restore in another AZ	Available in multiple AZ unless using OneZone
Pricing	Lower price compared to EFS	Expensive