Computer Data Storage Units

Units of Storage

• The basic unit of computer data storage is the bit (binary digit), composed of ones and zeros.
• Calculating storage involves multiplying when moving from a larger unit to a smaller unit and dividing when moving from a smaller unit to a larger unit.

Cloud Storage

• Cloud storage refers to storing data on remote servers accessible through the internet.
• Examples include cloud storage services.
• Pros of cloud storage:
  • Accessibility: Access data from anywhere with an internet connection.
  • Collaboration: Many cloud storage services offer collaboration features for real-time editing and sharing.
  • Cost savings: Short-term cost savings, but costs can accumulate over time.
• Cons of cloud storage:
  • Requires internet connection: Access to cloud storage depends on a reliable internet connection.
  • Disaster recovery: Off-site data storage enhances disaster recovery capabilities.
  • Security concerns: Risk of data breaches and security glitches.

Local Storage

• Local storage refers to physical hardware kept nearby for storing data and information.
• Examples include external hard drives, flash drives, CDs, etc.
• Pros of local storage:
  • Complete control: User has complete control over access to files, ensuring security.
  • Easy access: Data can be accessed quickly and easily without an internet connection.
• Cons of local storage:
  • Manual backup: User is responsible for manually saving and backing up data to prevent loss.
  • Space constraints: Local storage takes up more space.
  • Limited collaboration: Difficult to collaborate with others, requiring manual upload and sharing.

Formula and Functions in Excel

• A formula is an expression that calculates the value of a cell and must start with an equal (=) sign.
• Functions are predefined formulas available in Excel.

Date Function

• The DATE function creates a date based on individual components: year, month, and day.
• Syntax: =DATE(year, month, day).
• Example: =DATE(2023, 5, 8) for May 8th, 2023.

IF Function

• Returns one value if a condition is true and another value if it's false.
• Example: =IF(A2>B2,"Over Budget","OK").

Product Function

• Multiplies all numbers given as arguments and returns the product.
• Formula: =PRODUCT(range).

Average Function

• Returns the average (arithmetic mean) of the arguments.
• Formula: =AVERAGE(range), e.g., =AVERAGE(A1:A20).

Count Function

• Counts all cells that contain values only.
• If used to count cells with alphanumeric values, it returns a zero (0).
• Formula: =COUNT(range), e.g., =COUNT(A4:A10).

CountA Function

• Counts cells that contain labels, values, or both.
• Formula: =COUNTA(range), e.g., =COUNTA(A4:A10).

CountIF Function

• Counts the number of cells in a range that meet a given condition.
• Counts labels, values, or both.
• Formula: =COUNTIF(range, "condition"), e.g., =COUNTIF(A4:A10, "red").