Keyword – definition and meaning

A keyword may refer to a word we use when searching for something on a database. It may be a word that a search engine sells to an advertiser. Google and Yahoo, for example, are browsers with powerful search engines.

The word may also mean the main word, one that we use a lot, or a word that defines a particular subject. In other words, a concept or word of great significance. For example, a politician may say “Inflation is the keyword in our election campaign.”

In cryptography, we use keywords as keys for breaking a code.

The Oxford Living Dictionaries has the following definitions for the word:

“1. A word or concept of great significance. 2. A word used in an information retrieval system to indicate the content of a document.”

“3. A significant word mentioned in an index. 4. A word which acts as the key to a cipher or code.”

With the meaning ‘word which serves as a guide to other words or matters,’ the term first emerged in 1807. In 1967, it acquired the additional meaning ‘word from the text chosen as indicating contents of a document.’

The word ‘keyword’ is a composite word, i.e., it consists of two words combined. The two words are ‘key’ and ‘word.’ In this context, the word ‘key’ means ‘vital, important, crucial.’

Keyword – Search engine optimization

In search engine optimization (SEO), keywords are particular phrases or words that describe a web page’s contents.

They are shortcuts that summarize a whole web page. They form part of a web page’s metadata. The words help search engines such as Google match a web page to a specific search query.

Keywords once had a very important role in the function of search engines. They would crawl websites and if the specific words were a good match, present those web pages as search results.

However, some webmasters started overusing them. This made search engines serve up unrelated sites in their search results.

Therefore, the importance of keywords in SEO has declined. Keywords still represent an important contributor to SEO. However, search engines now take into account other factors too.

Keyword density

If a keyword appears 20 times on a web page that has 500 words, its keyword density is 4%.

Although keywords are important for search engine optimization, webmasters must not flood their web page with them.

SEO experts warn against having a high density because search engines may treat them as search spam. In fact, they will penalize that web page, and possibly the whole website.

The terms ‘Web page’ and ‘Website’ do not mean the same. A website or site is a virtual location on the web with at least one web page. Let’s imagine a physical book. A web page is like a page in the book, while the website is the whole book.

Keyword cipher

In cryptography, people use a keyword as a key. In other words, they determine the letter matchings of the cipher alphabet to our normal alphabet.

Cryptography or cryptology is the art of solving or writing codes.

Cryptographers remove repeats of letters in the word. They then generate the cipher alphabet with the keyword matching to A, B, C, etc.

They do this until they have used up the keyword. Cryptographers then use rest of the ciphertext letters in alphabetical order, excluding those they had already used in the key.

Video – What is a keyword?

This Touching Clients video explains what keywords are. They are specific phrases or words that help search engines present appropriate web pages in response to a search query.