A free course on the basics of Java is provided by Microsoft, written by in-house employees. It comprises twenty-one YouTube videos and a Github repo where the associated exercises reside. The videos are deliberately short as they are targeted at complete beginners, But don't let that discourage you because the content is well presented is on modern Java can aid in freshening up the concepts for the more experienced audiences. The introductory video, 'What is Java' does a good job in disambiguating Java the language from Java the platform. It also mentions the recently acquired Native executable options and serves as a quick birds-eye overview. Talking about modern material, the second video is on the Jshell read-evaluate-print loop, which full article on i-programmer: https://www.i-programmer.info/news/80-java/15392-take-microsofts-java-for-beginners.html
A dairy of my work.Just links to the full artices on i-programmer.info