Difference between indexed and crawling ?

[JohnVilson]

When search engines look through the content on your website, they are crawling your site. As they crawl your site, they index content that will appear in the search engine. However, an important thing to remember is that not all content is indexed. Search engines pick what content they will and won't index as they go through the crawling process.

[roger710]

Crawling is something like Search engine bots visited your site and indexing is saving your information in database..

[SanviMalhotra]

Indexing is where search engine has crawled the web and ranks the URLs found using various criteria and places them in the database, or index.

Crawling is where search engines spiders / bots move from web page to web page by following the links on the pages.

[saanvikadam]

Indexing is when a page gets into search engines, and Crawling is the process when the page gets fetched

[Venktesh]

There is a minute difference between crawling and indexing. Google crawl all website present in online ad then indexes it, it helps in getting better results. So indexing is same as the index of the book i.e. to minimize the searching effort.

[macpual]

CRAWLING
Crawling takes place when there is a successful fetching of unique URIs which can be traced from valid links from other web pages. It's like Pacman following all those dots and eating them, only that in the case of crawling, it's the search engine robots that follow the links.

INDEXING
Indexing takes place after a crawled URIs are processed. Note that there may be several URIs that are crawled but there could be fewer of them whose content will be processed through indexing. The following reasons could be the causes of non-indexing of a previously crawled page:

[djone]

Crawling means when a search engine spider/bot just visit your site page by page and check links of the site. While bot/spider check your site as well as save your site into its database sothat you can get easily be visible into search engine by sear query.

[hanhtrinhxanh20]

The engine visit your site and read its content means crawling, if it accepts your page the engine will index it. As scheduled the engine visit your indexed page again and see how it changes.

[ZestApps]

CRAWLING

It is the process of an engine requesting and successfully downloading a unique URL. It's the search engine robots that follow the links.

These are the reasons why crawling wouldn't take place 
a. Using JavaScript format in Link coding which is also known as spider trap.
b. Contain no follow directive in a page where link was marked.
c. Maintenance issue of server when link was supposed to be crawled.


Indexing

The result of successful crawling leads to URL's presence in the Google index.
Remember that there may be several Urls are crawlwd but there could be some of them whose content will be processed through indexing.

Reasons behind why Google not indexing any URLs
a.Duplicate  content issue: A page that has the same content with an indexed page would not be indexed.
b. A no index directive in the page. (<meta name="flowers" content="noindex" />)

[Ajinkya Samark]

Hi,
Crawling is the process of an engine requesting and successfully downloading a unique URL. Crawlers get their URIs from a crawling engine that's feeded from different sources, including links extracted from previously crawled Web documents, URI submissions, foreign Web indexes, and whatnot.

Indexing is the result of successful crawling. I consider a URL to be indexed (by Google) when an info: or cache: query produces a result, signifying the URL's presence in the Google index. Obstacles to indexing can include duplication, unreliable server delivery and so on.