An aggregate is a collection of materials gathered to create a total quantity. An aggregator is a website/computer software that aggregates a specific type of information from multiple online sources. Examples of aggregators are Google, Ask Jeeves, Bing, Yahoo, and so on.
A pro to an aggregator is all information for a certain topic is listed so that the user can research and find information more easily. On an aggregation website, the user can enter in the keywords at the top of the page in the search bar and all relevant information will show up for easy exploring and investigating.
A con of aggregation website is not all the articles, web search results are of reliable sources. This could affect the users research as some of the information they gather might not be true.