Table 2.

Description of available eUtils tools

Tool name	Description
EInfo	Provides information about available databases or a specific database, such as: the number of indexed records for each searched field, the date of the last update, and available links to other NCBI databases.
EGQuery	Responds to the query returning the number of records that match the specified, search phrases in any Entrez database.
ESearch	Responds to the query returning a list of unique identifiers (UID) of records that match the specified query.
ESummary	For the specified list of UIDs, returns summaries of records from a particular database.
EPost	Accepts a list of UIDs and sends it to the History Server, returning the appropriate address in the form of parameters: WebEnv and query_key.
EFetch	Responds to the list of UIDs returning complete records from a specified database.
ELink	Allows traversing between databases using related UIDs. Returns the list of UIDs of records from a destination database related to the UIDs of records from the source database.
ESpell	Returns suggestions of the correct spelling for the query entered by the user.