Plagiarism is defined by the Committee On Publication Ethics (n.d.) as the use of another persons' work, without appropriate acknowledgement and/or as if it were their own.
Why is it important to avoid plagiarism?Conforming to ethical research standards and ensuring that your work is not plagiarized, is imperative to the integrity of your research and reputation as a researcher. Particularly when publishing, the integrity of your work is also a reflection of your research institution, the journal, the publisher, as well any colleagues, societies, contributors, funders and other parties affiliated with your research.
Committee on Publication Ethics. (n.d.). Plagiarism. https://publicationethics.org/category/keywords/plagiarism
Using someone else's work without proper acknowledgement is plagiarism, regardless of whether the act is intentional or unintentional. This applies not only to text, but to any form of intellectual property, including but not limited to:
Works (print or electronic), verbatim text, data, facts, findings, results, images, photographs, artistic works, graphics, infographics, designs and programs, ideas, theories, inventions, etc.
There are many forms of academic misconduct that constitute plagiarism, that range in severity. While the categories of plagiarism are numerous, a few prevalent forms to briefly note are:
Further information on prevalent types of plagiarism can be found in the resources tab.
Copyright relates to the rights that a Copyright owner holds over their works and intellectual property. This includes deciding usage terms and fees, how the work must be acknowledged, or whether it is allowed to be used at all. By plagiarizing someones work, you may also be breaching Copyright. This can have legal and financial repercussions.
When planning to display images, infographics, data etc. in your publication that have been taken from other sources, ensure that you have permission to do so and that they are correctly acknowledged. If in doubt, seek permission from the Copyright owner.
Some publishers may claim Copyright ownership over 
a work once it has been published in their journal - and in such instances, Copyright no longer belongs to the author/s. Always check the publishers policy on Copyright ownership when submitting your paper, as this determines how an author is allowed distribute and reuse their published work.
Readily available Copyright fact sheets can be found at Australian Copyright Council