Plagiarism, the act of copying the complete words, sentences, and idea without receiving someone's consent (This is my word, inspired by these three definitions, which are from Oxford, Cambridge, and Meriem-Webster's).
Yes, the first step that you should have done in understanding plagiarism is by trying to understand what exactly is a plagiarism. According to Oxford Online Dictionary, "plagiarism is the practice of taking someone else's work or idea and passing them off as one's own", whereas Cambridge Online Dictionary defines, "plagiarism is the use of another person's ideas or work and pretend that it is your own". To be summarize, plagiarism is similar to the act of stealing someone's work and in the academic field (particularly for scientific articles), this act is not appreciated due to the hard efforts made the original authors.
Why does plagiarism happen?
(1) Plagiarism is the representation of another author's language, thoughts, ideas, or expressions as one's own original work (wikipedia.org)
then, the other quotation is
(2) Plagiarism is the representation of another author's language, thoughts, ideas, or expressions as one's own original work (Random House Compact Unabridged Dictionary; Oxford English Dictionary in wikipedia.org)
in this style, the references - called as citation - is quite confusing due to the word "in wikipedia.org". This kind of style sometimes can be found when an author tends to quote some words or understandings from a book chapter, in which each chapter has different authors. Another style of quotation can be seen in like this,
(3) Simple understanding of plagiarism is the act of copying another writer's words expressions and ideas, and these two expressions are claimed to be his original work (wikipedia.org)
or,
(4) Simple understanding of plagiarism is the act of copying another writer's words expressions and ideas, and these two expressions are claimed to be his original work (Random House Compact Unabridged Dictionary; Oxford English Dictionary in wikipedia.org)
Now, we have 4 different styles, in which the last two sentences are famous with the term of "paraphrasing". However, from these four styles, which one is not considered as the act of plagiarizing? Well, the answer is none of them. The questions is how?
Now, let's go back again to the definition of plagiarism which is defined by both Oxford and Cambridge Online Dictionary. As it is written with quotation marks,
"plagiarism is the practice of taking someone else's work or idea and passing them off as one's own" (Oxford Online Dictionary)
Plagiarism is an act of stealing of someone else's work and ideas. Then, how we can differentiate the work and ideas? idea is something abstract, that cannot be defined via our senses. Because of that, we must acknowledge the idea of someone due to certain aspects, and one thing that is certain, is the originality. The process of appreciating someone's idea is by writing a citation. In this case, the examples of citation is those that are written in brackets (), or it is commonly written by last-name of the authors with the year that the idea is proposed, such as (Smith, 2021).
The other thing that we must acknowledge is the "work". The word work can be defined in many features, such as the methods, the results or data, interpretation of something, and even more the conclusion. This is the reason why lots of experienced authors quoted the others authors results in supporting their findings. However, from these four features, there is one thing that is neglected. It is the "words", the "statement", the "text". Therefore, paraphrase is the process of acknowledging someone's work, which is the textual, or in this case is "plagiarism is the practice of taking someone else's work or idea and passing them off as one's own". So? what about style number (4)? and what about images? these two would be discussed in my next article.
In conclusion, plagiarism can be avoid by acknowledging the idea first by writing the citation. Furthermore, the acknowledgment of the "work" can be done by doing paraphrasing.