An abstract is a summary of the article, and will give you an idea of what the article is about and how it will be written. If there are lots of complicated subject-specific words in the abstract, the article will be just as hard to read.
This is where the author will repeat all of their ideas and their findings. Some authors even use this section to compare their study to others. By reading this, you will notice a few things you missed, and will get another overview of the content.
This is usually where the author will lay out their plan for the article and describe the steps they will take to talk about their topic. By reading this, you will know what parts of the article will be most relevant to your topic!
These are called topic sentences, and will usually introduce the idea for the paragraph that follows. By reading this, you can make sure that the paragraph has information relevant to your topic before you read the entire thing.
Now that you have gathered the idea of the article through the abstract, conclusion, introduction, and topic sentences, you can read the rest of the article!