People choose to volunteer for many reasons. For some it offers the chance to give back to the community or make a difference to people around them.
For others it provides an opportunity to develop new skills or build on existing experience and knowledge.
Now Australians are being urged to give a wave of support to these millions of volunteers dedicating time to help others.
National Volunteer Week, May 17-23, is Australia's largest annual celebration of volunteers.
To mark the week Volunteering Australia is urging everyone to put their hands up and show support for these selfless individuals by posting photos of themselves waving, with the hashtag #waveforvolunteers, on social media.
One lady who deserves a show of hands is centenarian Bessie Conomos.
Born in Greece, cooking has never been a chore, but a passion she is keen to pass on to others.
The Brisbane senior, who at the age of 87 was was recognised in the Australia Day Honours List for her service to the city's Greek community including helping organisations which help the elderly, recently celebrated her 100th birthday at Carinity Wishart Gardens aged care community.
Born Vasilike Gianniotis on the small island of Kythira in Greece in 1921, Bessie migrated with her parents to New South Wales seven years later. She eventually settled in the small town of Carinda, two-hours drive from Bourke, with her husband Theo.
The tireless volunteer was actively involved in the community and also in other regional towns such as Walgett and Dubbo, before the Conomos family moved to Mansfield in Brisbane in 1984.
There she volunteered for Meals on Wheels and also at the St Nicholas aged care home in Highgate Hill and the Greek Orthodox Church at Mt Gravatt.
Bessie's love for cooking and her talents in the kitchen helped drive her fundraising for numerous charities.
Her OAM also recognised Bessie's contributions to the community of Carinda, particularly as an avid member of the local Country Women's Association and Bush Nursing Association.
"Mum always hoped she inspired young people to become involved in their communities. She loved to cook and was an avid knitter," said daughter Regina.
Helping suits Susan to a tee
According to Volunteering Australia, over 80 per cent of residential aged care facilities and half of home support programs engage the services of volunteers.
There are almost 300 volunteers across South Australian not-for-profit aged care organisation ACH Group, including Susan Field, who gives her free time to support a range of social experiences, group activities and programs.
For Susan, volunteering at ACH Group's Yankalilla Centre residential care home was a natural choice, as her career was dedicated to the aged care sector.
"I worked in aged care for 26 years in various residential care homes in Adelaide.
"When I moved to Normanville, I knew I wanted to find somewhere in the area where I could continue to contribute," she said.
Susan said while she had experience in aged care, it was not essential.
"You do not need a skillset or previous experience in aged care to volunteer here; you need empathy and kindness," she said.
ACH Group's Volunteer Manager, Tay Parker,said volunteering is a 'win-win' for all.
"ACH Group is extremely fortunate to have a large group of passionate volunteers, dedicated to supporting good lives for older people."