Few people can write an essay straight off without gathering a few ideas first. Even in an examination, when a topicSee the glossary definition is given, it pays to spend a few minutes thinking about what you are going to write and how you will organise your essay.
BrainstormingSee the glossary definition is often thought of as a group activity but it's just a fancy word for thinking; gathering some ideas in whatever way you find most productive.
You probably have your own method. Perhaps it's just a question of scribbling down a few ideas on a piece of paper. There's nothing wrong with that, except that you might easily misplace that paper. Perhaps you have a notebook where you keep your ideas - better. Or perhaps you keep your notes on your phone, laptop or other device. If you do, make sure it's all backed up so that you can always access it from another device.
One important disadvantage of using paper is that sooner or later you'll have to transfer these ideas to a text processor on a device. That may not be a problem if you just a few ideas for a short essay but if your text is going to be lengthy then you'll probably have a lot of notes to transfer. Moreover, if your paper is a research paper you'll have a number of quotations, text you want to paraphraseWrite a short version of someone's text in your own words. See the glossary definition , citationsSee the glossary definition and a bibliographicSee the glossary definition reference for each of these. This means you need to have a place where you can keep all your ideas, quotes, citations, etc. so that you can copy and paste them into your text once you start writing your first draftSee the glossary definition . One way to do this is to use a mind mapping app. There are many other ways but if you are a visual thinker, this can be a good option.
There are many mind map apps available to choose from and some people find them useful. This is not the only way to brainstorm and organise your ideas and sourceSee the glossary definition material, but you do need some system, especially for large projects such as long essays and research reports.