A search method is a way of efficiently and effectively finding the information you need to answer your research question.
The snowball method is a way of finding literature by using a key document on your subject as a starting point.
Consult the bibliography in the key document (book or journal article) to find other relevant titles on your subject.
You then look in the bibliographies of these new publications to find yet more relevant titles.
The advantage of the snowball method is that you can find a lot of literature about a subject quickly and relatively easily.
The disadvantage of this method is that you are searching retrospectively, so each source you find will be older than the previous one (especially in the case of books).
You are searching in a focused way. This increases your chances of finding relevant information.
Because your search is focused, you will spend less time reading irrelevant material.
Which search method is best suited to your research depends on both the subject of your research and the kind of text you have to produce (essay, paper, thesis, article). In many cases you will use a combination of search methods.
This method involves searching in SmartCat or databases (including library databases) using subject terms.
Look through the initial search results and try to find better search terms, then search further using the new terms.
Many of the publications you find will contain relevant bibliographies. The disadvantage is that these titles always pre-date the publication in which they are mentioned.
Citation searches reverse this process: who has cited the publication you have found? In this way you will find recent literature.
Some databases (e.g. Web of Science) have this option.
Citation searching in Web of Science