What is the difference between apt-get install and apt install?

The primary difference between `apt-get install` and `apt install` is that the former is a stable, low-level command from the original APT suite, while the latter is a newer, user-friendly command from the `apt` package that provides a more intuitive interface and some visual enhancements. Both commands ultimately use the same underlying APT library to manage packages on Debian-based systems like Ubuntu, ensuring identical outcomes for core operations such as installing, removing, or upgrading software. The distinction is therefore largely one of user experience and command syntax rather than functional divergence in package management results.

Mechanically, `apt-get` is part of the Advanced Package Tool suite, which includes several single-purpose commands like `apt-cache` and `apt-config`. It is designed for scripting and stable operation, producing plain, parseable output. In contrast, the `apt` command, introduced around 2014, consolidates the most commonly used features from `apt-get`, `apt-cache`, and `apt-config` into a more cohesive tool. For the `install` operation specifically, `apt` provides a clearer progress bar and color-coded output, and it explicitly lists the number of packages to be added or upgraded, which `apt-get install` does not show by default. However, `apt-get` remains the recommended tool for use in shell scripts due to its stable, predictable output format and its guarantee of backward compatibility.

The implications of this duality are significant for different user groups. System administrators and developers writing deployment scripts or cron jobs should continue to use `apt-get install` because its behavior and output are strictly defined and less likely to change between releases, ensuring script reliability. For interactive use by regular users or in documentation aimed at human readers, `apt install` is often preferable due to its clearer feedback and reduced typing. It is important to note that `apt` does not encompass all the functionalities of the `apt-get` suite; certain lower-level operations, like `apt-get download` or `apt-get source`, are not directly available in the `apt` command, necessitating a fallback to the traditional tools.

Ultimately, the choice between the two commands hinges on context: `apt-get install` is the robust, script-oriented workhorse, while `apt install` serves as a streamlined front-end for interactive terminal sessions. Both are fully supported and will perform the same package installations, but their differing design philosophies cater to distinct workflows. The ecosystem maintains both to balance the needs for innovation in user experience and unwavering stability in automated system management.