jMeter Variables are similar to properties , but they are local to a single thread

String name = vars.get("myname"); // get ${myname} variable value from input(it may be csv input, user defined variable, etc)

log.info("\n\nName : "+ name  );

String title = name + " Welcome";

log.info("\n\ntitle  : "+ title   );
 
vars.put("title", title); // put new value into ${title} variable

log.info("\n\ntitle from vars  : "+ vars.get("title") );

In properties

${title}

ref: https://jmeter.apache.org/api/org/apache/jmeter/threads/JMeterVariables.html