Terms and Acronyms

AMI – Amazon Machine Image – The Software

A read-only image of a file system that includes an Operating System (OS) and additional software installed. Conceptually, this is comparable to a CD/DVD that contains an OS and other software that is installed on a “machine” for you. The creator of the AMI chooses which OS to include and then installs and configures other software. For example, an AMI creator might choose to start with CentOS Linux or Ubuntu Linux and then pre-install a set of tools that are useful for a particular purpose.

An AMI might be created for Photo Editing which would contain a pre-installed suite of software that the AMI creator deems is useful for Photo Editing.

An AMI might be created for Neuroimaging with a chosen OS (e.g. Ubuntu 12.04.1 LTS) and a pre-installed suite of software for Neuroimaging (e.g. FSL, AFNI, FreeSurfer, the HCP Pipelines, Workbench, etc.)

The AMI is the software distribution that will be installed and run on your virtual machine instance (see below.)

AWS - Amazon Web Services

A collection of remote computing services that make up a cloud computing platform. The two of the central services are Amazon EC2 (the service that provides compute power, “machines” that are remotely available) and Amazon S3 (the service that provides storage space for your data).

EBS – Elastic Block Storage

Online data storage service that provides a more traditional file system. An EBS volume is attached to a running EC2 instance. From the EC2 instance’s point of view, an EBS volume is a “local drive”.

EBS volumes can be configured such that the data continues to exist after the EC2 instance is shut down. By default, however, they are configured such that the volume is deleted upon instance shut down.

EC2 – Elastic Compute Cloud

Amazon service that allows users to rent virtual machines (VMs) on which to run their applications. Users can create, launch, and terminate VMs as needed, paying an hourly fee only for VMs that are currently active (this the “elastic” nature).

EC2 Instance Types – The available hardware

An EC2 Instance Type is a particular combination of CPU, memory (RAM), storage, and networking capacity optimized for a particular purpose. There are instance types defined for use as:

  • General Purpose systems
  • Compute Optimized (e.g. high performance) systems
  • Memory Optimized systems
  • GPU application systems
  • Storage Optimized (high I/O) systems

An Instance Type is a virtual hardware configuration.

EFS - Elastic File System

A rented FILE SYSTEM that can be mounted on multiple EC2 instances.  Can even be mounted on your “local” computers, but requires special AWS Direct Connect connection to Amazon bypassing standard internet connection

S3 Bucket

Data in S3 is stored in buckets. Forour purposes, a bucket is simply a named container for the files that we store and share via Amazon S3. HCP’s data is made available publicly in a bucket named hcp-openaccess.

S3 – Simple Storage Service

Amazon online data storage service. Not a traditional file system. Stores large “objects” instead of files. These objects are accessible virtually anywhere on the web. Multiple running EC2 instances can access an S3 object simultaneously. Intended for large, shared pools of data. Conceptually similar to a shared, web-accessible drive.

VPN - Virtual Private Network

A Virtual Private Network is a service that allows you to connect to the Internet via an encrypted tunnel to ensure your online privacy and protect your sensitive data. A VPN is commonly used to secure connection to public Wi-FI hotspot, hide your IP address and make your browsing private.  Your institution might ask you to connect to their resources after signing into (turning ‘ON’) a VPN through clients such as the ‘Cisco AnyConnect Secure Mobility Client’.  

VNC viewer

Virtual network computing (VNC) is a type of remote-control software that makes it possible to control another computer over a network connection. … It also interprets commands coming from the viewer and carries them out on the remote computer. VNC is platform independent and is compatible with any operating system.

WB - Connectome Workbench

Connectome Workbench is an open source, freely available visualization and discovery tool used to map neuroimaging data, especially data generated by the Human Connectome Project.  Learn more at https://www.humanconnectome.org/software/connectome-workbench.

Amazon VPC - Amazon Virtual Private Cloud

a logically isolated section of the AWS cloud where you can launch AWS resources in a virtual network that you define


Neuroimaging Informatics Tools and Resources Clearinghouse, makers of the NITRC Compute Environment, NITRC_CE