The definition of volunteering has evolved, for sure, but essentially when somebody assists others outside their household without financial compensation and for the public good, that's considered volunteering.
Over time there's been an acceptance that there's a spectrum of involvement, so it could be somebody who keeps themselves informed about an issue. If they're interested in recycling or youth homelessness, they keep themselves informed on the issues. Further along, they may actually do something to support that issue, and further along they may actively participate with an organization or informal—