Learn the difference between the Crawl Rules and a Crawler Impact Rules here :
Crawl rules provide you with the ability to set the behavior of the Enterprise Search index engine when you want to crawl content from a particular path whereas a crawler impact rule defines the rate at which the Windows SharePoint Services Help Search service requests documents from a Web site during crawling. The rate can be defined either as the number of simultaneous documents requested or as the delay between requests. In the absence of a crawler impact rule, the number of documents requested is from 5 through 16 depending on the hardware resources.
Using Crawl Rules You can "Prevent content within a particular path from being crawled" & "Indicate that a particular path that would otherwise be excluded from the crawl should be crawled"
A detailed information of "how to manage your Crawl Rules" is specified in the Microsoft Technet Site here.
A detailed information of "how to manage your Crawl Impact Rules" is specified in the Microsoft Technet Site here.
Note : Hands-On will certainly help
Crawl rules provide you with the ability to set the behavior of the Enterprise Search index engine when you want to crawl content from a particular path whereas a crawler impact rule defines the rate at which the Windows SharePoint Services Help Search service requests documents from a Web site during crawling. The rate can be defined either as the number of simultaneous documents requested or as the delay between requests. In the absence of a crawler impact rule, the number of documents requested is from 5 through 16 depending on the hardware resources.
Using Crawl Rules You can "Prevent content within a particular path from being crawled" & "Indicate that a particular path that would otherwise be excluded from the crawl should be crawled"
A detailed information of "how to manage your Crawl Rules" is specified in the Microsoft Technet Site here.
A detailed information of "how to manage your Crawl Impact Rules" is specified in the Microsoft Technet Site here.
Note : Hands-On will certainly help