Using references is a way of honouring the original author of the text, the person who took the picture or the creator of the table: give credit where credit is due and tell others honestly if quoted. Copyright protects both texts and other materials. Plagiarism and unauthorised copying are punishable. Often plagiarism is unintentional and it is worth learning about referencing practices to avoid it. Material produced by another person can be used under certain conditions, provided that the author has given permission, for example under a Creative Commons licence.
In your text, seek to engage in dialogue with your own thinking and the research results, findings, claims, etc. found in the source material. The fact that you say where your ideas come from makes your text polyphonic: you cannot present someone else's ideas as your own, but you can say "I agree/disagree with xx that...". Always remember to justify your views, as this shows that you have thought about the issue and can apply what you have learned.
The text could go like this:
Platts, Breckon and Marshall (2022) found in their study that the sudden transition to remote work due to covid-19 had a negative impact on participants’ well-being at work. I agree, because...
And in the references:
Platts, K., Breckon, J., & Marshall, E. 2022. Enforced home-working under lockdown and its impact on employee wellbeing: a cross-sectional study. BMC Public Health, 22(1), 1–13. https://doi.org/10.1186/s12889-022-12630-1. 16.3.2023.
Please note that copyright also protects your own rights, for example your thesis and other texts you have written. When you publish your thesis on Theseus, you can define the rights of others to use it (Theseus guidelines).
When writing a thesis in particular, you must also bear in mind the need to follow good scientific practice. You can find more information on this on The Finnish National Board on Research Integrity TENK's website.