echo() and print() are language constructs in PHP, both are used to output strings. The speed of both statements is almost the same.

echo() can take multiple expressions whereas print cannot take multiple expressions.

Print return true or false based on success or failure whereas echo doesn't return true or false.

DispatchAction is an action that comes with Struts 1.1 or later, that let us combine Struts actions into single class, each with their own method. The org.apache.struts.action.DispatchAction class allows multiple operations to map to the different functions in the same Action class.

For e:g; html:hidden property="dispatch" value="error"/>

<SCRIPT>function set(target) {document. forms[0].dispatch. value=target;}</SCRIPT>

- Web servers can be infiltrated using the command shell by an attacker to read the HTML files that is getting transferred. 

- If the set-uid scripts are not proper and bad then the infiltration can happen by the attacker. 

- The processes are not given proper permissions so that the password can be changed by using the “passwd” command to change the password of the system.

- This also authenticates the user for accessing the system and the files on it containing the data. 

- The program that is used in the operating system doesn’t follow the principle of least privilege and lead to security issues.

- Fail-safe approach defines the level that divides the security such that it is safe even in case the system is failed.

- The fail safe approach doesn’t allow an attacker to take the advantage by breaking in the system and crashes out.

- This approach allows the web server to perform the routines even if the system runs out of the memory in case of any attack. 

- The system in attacks doesn’t skip the access to the control check or it doesn’t skip serving any document requested. 

- Fail safe approach can force the web server to run of the memory and have a DoS attack.

The cookie settings include the enabling and disabling of the services that are used with the web browsers.

The following steps are taken to set the cookies:

- The TOOLS menu is being opened on web browser and the privacy tab is selected from where the privacy of individual user can be managed. 

- Using the ADVANCED tab the options to set the cookies will be visible and it will allow the overriding of cookie. 

- The cookies can be accepted by checking the first party cookies or the third party cookies. Out of these choices the first party cookies provide more security. 

- Check the checkbox for "Always allow session cookies" so that the session cookies can be maintained. 

- Files can be transferred to the server by using the FTP protocol also known as File Transfer Protocol. 

- FTP is used as a standard network protocol that transfers the file from one computer to another computer using the TCP protocol network.

- This uploads the pages and other documents that are stored in private disk to the public web hosting server. 

- FTP is used on a client server architecture that allows different controls and data connections between the client and the server. 

- FTP uses clear-text sign in protocol that allows the client to use the user name and password for authentication purpose.

drawImage(image,x,y) method is used to draw an image on the canvas.

Following JavaScript objects are not accessible to web worker: 

- The window object

- The document object

- The parent object