Journals have strict page limits so there's no space to introduce domain specific terminology or give a brief tutorial on the topic. They only have enough room to tersely describe directly relevant background material and will assume you are knowledgable in the domain.
Read the abstract then the conclusion. If it sounds like you want to understand the rest of the paper after that, be prepared to look up terminology, read citations, follow tutorials and reread the paper multiple times to really understand it. Don't be put off if you can barely understand it the first time.