FILES AND DIRECTORIES INFORMATIONFiles and directories. File information.

CONTENTS

1. Files and directories
2. File name
3. File types
4. File size and units of measurement
5. Creation and modification dates
6. File path

FILES AND DIRECTORIES

A file refers to data stored on a hard drive or other storage media as a separate entity.

Files typically have the following characteristics:

• A file always has a name.
• A file always takes up storage space.
• A file is always saved in a certain format: a body of text is saved in one of the many text file formats, a photo in one of the many image file formats, etc.
• A file contains information on when it was created and when it was last modified.
• Files usually have access rights, especially if they are online.
• Files are saved on the user’s own computer or in a remote location.

FILE NAME

The naming conventions for files and directories vary by operating system.

in OS Windows, for example, the dot in the file name is usually followed by a file extension consisting of one or several characters that indicate the file type. In OS Linux, on the other hand, no extension is necessary.
Depending on the system, it may not be possible to use certain special characters (: > / * ? ” > |) in the file name. In addition, using a space or Scandinavian umlauts (å, ä, ö) may sometimes cause problems, especially over the Internet. If you have trouble posting files online, try removing special characters from the name.

In Linux, the use of upper case and lower case letters in file names makes a difference; e.g. Test.txt is different from Test.txt. In Windows, upper and lower case letters can be used more freely.

FILE TYPES

A file can contain different kinds of material: text, video and so forth.

When the contents of a file are saved in a certain generally known format, it is called a file type. Photographs, for example, are often stored as JPEG image files, and word processing documents as DOCX or RTF document files.

In Windows, the file type is evident from the file extension (usually consisting of three letters) that follows the dot in the file name. The file extension indicates the format in which the data in the file has been stored.

Be careful when dealing with file extensions in operating systems, including Windows.

If you change an extension or leave it out, the operating system might not know which application to use to open the file.

Opening the file through the correct application will also be more difficult because the file will not be displayed in the default view.

FILE SIZE AND UNITS OF MEASUREMENT

Understanding file sizes is very useful.

Too big a file sent as e-mail may completely fill the recipient’s mailbox or it may cause your message not to leave at all. Similarly, you may not be able to save several large files on a USB flash drive if you don’t know how to estimate the total amount of space they need.

Data is saved in binary form, i.e. as numbers consisting of ones and zeros. The smallest data storage unit – the bit (b) – can receive the value 1 or 0. When several bits are combined in a row, they form a byte (B). A byte may look like this, for example: “01011001”. If you type the word “data” on your computer, it consists of four bytes (each letter usually consists of one byte).

The storage capacity is specified as the maximum number of bytes that the storage media can hold.

The storage capacity is often so large that it is described as follows:

Unit	Abbreviation	Size in bits or bytes
Byte	Byte (B)	1 byte = 1 character = 8-bit string
Kilobyte	kB (KByte)	1024 Bytes
Mega Byte	MB (MByte)	1024 Kilobytes
Gigabyte	GB (GByte)	1024 Megabytes
Terabyte	TB (TByte)	1024 Gigabytes

Note: For more information see International System of Units (SI).

CREATION AND MODIFICATION DATES

Controlling the date and time of file creation, editing and access is of utmost importance for system security.

The creation and modification dates are then shown as follows:

Created:	Monday, September, 26, 2016, 16:42:36
Modified:	Tuesday, September, 27, 2016, 18:22:12
Accessed:	Today, October, 8, 2016, 23 minutes ago

PATH

A directory or folder is a place where files or other directories are saved.

A string of text that shows the location of a file or directory is called a Path.

The path to a file on the hard drive of work station (OS Windows) can be e.g.:

C:\Users\Test\Images\Photo001.png

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