Compression software - Answers
Q1. A zip file is another name commonly used for a compression file.
Q2.Compressed files are smaller than the original contents.
Q3. The unit used to measure file size is the byte (Kbyte, Mbyte, Gbyte).
Q4. How file compression is achieved:
You would need 50 * 9 = 450 bytes to store all of the characters in elephant fifty times.
The file compression software creates a dictionary and puts elephant in it.
It also gives elephant a code, let us say E to keep it simple.
Now it replaces all the instances of elephant in your document with E.
That's it! All you need now are 50 * 1 = 50 bytes to store your document (and a little bit for the dictionary). Instead of 450 bytes, you only need 50 bytes to store the word 'elephant'! If you did that for all the words in your document, you would soon have a much smaller document. You've now created a zip or compressed document. If you wanted to unzip it, or decompress it, you just get some compression software to put the words from the dictionary back into the document.
Q5. If you want to save lots of photos and videos on your pen drive but they won't fit, compress them using e.g. 7-Zip.
Q6. Video streaming is when a video is being watched over the Internet at the same time it is being sent.
Q7. Videos compressed during the streaming process because they are large files. The idea is to try and send as much of the file in as little time as possible so that the viewer can watch it while the next bit is being sent.
Q8. Open source software is software that is free to modify, distribute and use.
Q9. One open source application for compressing files is 7-Zip.
Q10. Visit here and read how files are compressed.