The basic search feature in PubMed allows you to find literature quickly. From the basic search, you can enter search terms as well as commands.
A short video from the National Library of Medicine is available here:
It should be noted that this method is not adequate for projects requiring a thorough literature search (such as scoping and systematic reviews).
When you start to enter terms into the search field, you will see a list of suggested terms appear below. This is call term mapping.
When you use no quotation marks, tags or asterisks, PubMed uses an Automatic Term Mapping feature to search for:
in that order.
As soon as PubMed finds a match, the mapping stops. That is, if a term matches a subject, PubMed does not continue to look for that term as a journal. If no match is found, PubMed breaks apart the phrase and repeats the process until a match is found. Phrases and individual terms are also searched in All Fields.
Using quotation marks and truncation disables term mapping in PubMed.
When viewing an article record, you can see that the journal title and author names are displayed with blue text:
The blue text is hyperlinked to actions in PubMed.
To retrieve all citations from the displayed journal, click the journal's name and the select Search in PubMed from the dropdown menu.
When you click on an author's name, a PubMed search will be run automatically. Keep in mind that the results might include other authors with similar names, or that an author might be credited using other variations of their name.
When you are viewing an article record, you can view a list of records for similar articles. 
PubMed uses an algorithm to compare words from the Title and Abstract fields of each citation, as well as the assigned MeSH headings. The best matches for each citation are pre-calculated and stored as a set.
You may see a few citations without the Similar Articles link, which simply means that these citations have not yet gone through the algorithm. This process may take several days.
You can navigate to this section by clicking Similar articles under the "Page Navigation" section in the right column.