A swap is a space on a disk that is used when the amount of physical RAM memory is full. When a Linux system runs out of RAM, inactive pages are moved from the RAM to the swap space.
The shutter is a free and open-source, feature-rich screenshot tool for Linux-based operating systems such as Ubuntu.
Redis stands for "remote dictionary server" and is a key-value store that stores data as key-value pairs.
Nginx, pronounced like "engine-ex", is an open source web server. Nginx is known for its high performance, stability, and rich feature set.
The Apache HTTP Web Server (Apache) is an open-source web application for deploying web servers. This guide explains how to install and configure an Apache on Ubuntu 20.04 LTS.