Hi Amar Mohamed Ismail ,

Plagiarism is to write and use other's content as your own whether intentionally or unintentionally.

So, one must rephrase the sentence you find as plagiarized after checking through the software.

In my opinion, the best software to check and avoid the plagiarism is Turnitin .

Hope you got your answer........

Thanks and Goodluck

Thank you Deepak, yes, your answer is valuable.

See some online tools described as 10 Free Plagiarism Checker Tool for Thesis:

https://www.ilovephd.com/10-free-plagiarism-checker-tool-for-thesis/

Anton thank you for the plagiarism-chechers

Strategies to avoid plagiarism

1. Quotation marks

2. Author labels

3. System of separation

4. Read, then look away to write

5. Zotero's word plug-in

https://www.ilovephd.com/10-free-plagiarism-checker-tool-for-thesis/

www.grammar-quizzes.com › writing_plagiarism

https://writingcooperative.com/10-tips-for-students-how-to-avoid-plagiarism-in-your-writing-11892264deb

www.scribbr.com › Knowledge Base › Plagiarism

https://davidson.libguides.com/c.php?g=349327&p=2361770

https://copyleaks.com/plagiarism-checker/how-to-prevent-and-avoid-plagiarism

To check the plagiarism. the best option is turnitin. To avoid the similarity, the best way is paraphrasing the text.