Maven is a build automation tool used primarily for Java projects. Maven can also be used to build and manage projects written in C#, Ruby, Scala, and other languages. The Maven project is hosted by the Apache Software Foundation, where it was formerly part of the Jakarta Project. Wikipedia
Maven is a Java tool, so you must have Java installed in order to proceed.
Running this on Ubuntu, shows mvn is already installed. [This was installed because we ran this command previously
curl -O https://repo1.maven.org/maven2/com/microsoft/sqlserver/mssql-jdbc/8.4.0.jre14/mssql-jdbc-8.4.0.jre14.jar
abc@ubuntu:~/src/connector$ mvn --version
Apache Maven 3.5.2 (138edd61fd100ec658bfa2d307c43b76940a5d7d; 2017-10-18T18:58:13+11:00)
Maven home: /home/abc/bin/apache-maven-3.5.2
Java version: 14.0.1, vendor: Oracle Corporation
Java home: /home/abc/bin/jdk-14.0.1
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "5.4.0-45-generic", arch: "amd64", family: "unix"