Glossary of Terms

The following are some concepts and terms related to the BackOnline software:

Application Programming Interface (API)
APIs allow programmers to write programs which can work with a certain application for which the API is provided. In the BackOnline framework, programmers can use the BackOnline client side API to communicate with the BackOnline server for special cases. For example, programmers can store their application's data in the BackOnline server.
BackOnline Client
Clients are programs which communicate with another program, a Server, to carry out certain functions. Similarily, the BackOnline Client communicates with the BackOnline Server to store and retrieve the backup data requested by the user. The BackOnline Client can be run as an applet, GUI application or command-line utility.
BackOnline Server
Servers are programs which service requests of their corresponding client programs. The BackOnline Server provides services to the BackOnline Client such as storing incoming data, searching for remote documents, providing information on requested files, and more.
Compression
Compression allows data to be reduced in size. For example, BackOnline has the ability to reduce the size of a file by upto 550% prior to transmission and storage on the server.
Encryption
Encryption is a process of converting data from it's original form into something different, typically into "garbage" data which cannot be interpreted by other people. To convert the data back into it's original form, the data goes through a decryption process.
Encryption Key
When encrypting data, a key is used to "mangle" or encrypt the data. The same key is later used to decrypt the data. This key essentially "locks" and "unlocks" a user's data and hence must be kept a encryption. In the BackOnline framework, this key is typed in by the user on the login screen of the BackOnline client and is used for encrypting and decrypting the data (note, the key is actually never stored on disk anywhere).
Java
Java, developed by Sun Microsystems, is a programming language which allows creation portable bytes codes that can be run on several operating systems. Java can be used to create mini-applications known as applets which run inside Java enabled browsers such as Netscape Navigator and Microsoft Internet Explorer. Additionally, Java can be used to develop standalone GUI applications, command-line utilities and other things such as Serverlets, CORBA objects, etc..
Java Applet
Java applets are mini-applications which run inside Java enabled browsers such as Netscape Navigator and Microsoft Internet Explorer.
Java Application
These are stand-alone applications which be have a Graphical User Interface (GUI) such as Microsoft Windows's NOTEPAD or run on the command line such as the MS-DOS COPY utility.
Java Development Kit (JDK)
The JDK is the complete set of development tools required to write Java programs. Sun Microsystems provides the JDK for Windows 95/NT, Solaris, and Macintosh. JDK for other operating systems are available from third parties. For a list of supported operating systems, visit Sun's Java site at http://java.sun.com.
Java Runtime Environment (JRE)
The JRE is the minimum set of files required to run Java applications (not applets). The JRE essentially provides an interpreter which interprets Java byte code class files and executes them. Sun Microsystems provides the JRE for Windows 95/NT and Solaris. JRE for other operating systems are available from third parties. For a list of supported operating systems, visit Sun's Java site at http://java.sun.com.
Trusted Applet
Java applets, by default, cannot access a user's local disk or connect to servers other than the ones they were downloaded from. To get around these restrictions, the provider of the applet can digitally "sign" the applet which causes the browser to display a certificate identifying the origin of the applet to the user and requesting the user to either grant or deny privileges to the applet to get around it's restrictions. If the user "trusts" the provider of the applet and grants the privileges, the applet is allowed to access the user's local disk and connect to other hosts. The BackOnline Client must be granted these priviliges in order for it to operate.
Web Server
A Web Server typically services requests from a Web Browser for documents such as HTML files, GIF/JPEG images, and also Java applet byte codes. The Java applet byte codes, or .class files, are simply another file type. Sometimes, these .class files are bundled into an archive file for faster downloading. Netscape Navigator uses a JAR (or ZIP) file, while Microsoft Internet Explorer uses Microsoft's Cabinet file format (or CAB file for short). For using the BackOnline client as an applet, the appropriate files must be copied to a directory accessible by the web server.