Comet is a web application model in which a request is sent to the server and kept alive for an extended period of time until a time-out or a server event occurs.
Comet is also known as "Server Push", "Ajax Push", and "HTTP Streaming".

jQuery. jQuery's utility function is noConflict().
The noConflict() method frees the $ shortcut identifier, allowing other scripts to use it.

On the client side, the code used to generate graphics is typically much smaller than the images themselves, resulting in significant bandwidth savings.

The css() method sets or returns one or more style properties for the elements that have been selected.
The css() method operates on the jQuery object returned by $() and returns it, allowing the show() method to be called next in a short "method chain."

These characteristics are central to jQuery's power and utility:
An expressive syntax (CSS selectors) for referring to document elements
A quick way to find the set of document elements that match a CSS selector.
A useful collection of methods for manipulating specific elements.
Effective functional programming techniques for working with groups of elements rather than one at a time.
A concise idiom (method chaining) for expressing operation sequences.

The jQuery library includes a single global function known as jQuery ().
Because this function is so commonly used, the library defines the global symbol $ as a shortcut for it.
The $ sign is simply an alias for jQuery(), which is then an alias for a function that is used as a selector element.

The min denotes the library's minimal version, with unnecessary comments and whitespace removed and internal identifiers replaced with shorter ones.
Minfile's file size is smaller than the original file, making it easier to load.

An HTTP request is made up of four parts:
the URL being requested an optional set of request headers, which may include authentication information an optional request body

$() is simply a jquery alias function ().
The most important function in the jQuery library is jQuery() (also known as $()).
It is, however, heavily overloaded, with four different ways to invoke it.

Comet is the inverse of Ajax in that the web server initiates communication, sending messages to the client asynchronously.
Comet has the significant advantage of always having a communication link open to the server.