Module 4 — Software

Module 4 · week of 09/14/2026 · Tech+: Software (Lesson 2 Operating Systems, Lesson 4 Software and Applications) — OS functions, file management, application software, spreadsheets. · Download .docx

Objectives

Compare and contrast types of computers and application software.
Perform basic proficiency in data analysis using software.

Key terms

System software: Software that runs the computer itself — the operating system and utilities.
Application software: Programs that do work for the user — word processor, spreadsheet, browser.
Operating system (OS): System software that manages hardware, runs apps, handles files, and provides the interface.
User interface: The way a person interacts with software — windows, icons, menus, touch, voice.
File: A named collection of data stored on a device — a document, photo, or program.
Folder (directory): A container that organizes files and other folders in a tree.
File path: The route to a file through its folders, e.g. Documents/INT1010/hardware.docx.
File extension: The letters after the dot that identify a file's type (.docx, .xlsx, .pdf, .jpg).
Backup: A second copy of your files kept somewhere else in case the first is lost.
Cell: One box in a spreadsheet, named by column letter and row number (C4).
Range: A group of cells, written first:last (A1:A10).
Formula: An instruction in a cell that starts with = and calculates a result.
Function: A built-in formula such as SUM, AVERAGE, MAX, MIN, or COUNT.
Absolute reference: A cell address locked with dollar signs ($A$1) so it does not change when copied.
Open source: Software whose source code is public and free to use, change, and share.
SaaS: Software as a Service — software you subscribe to and run in the cloud (Microsoft 365, Canvas).

The concept

Two kinds of software: system software (the operating system and utilities that run the computer) and application software (the programs you use to get work done).

The operating system (OS) manages hardware, runs applications, controls the file system, and gives you the user interface. Examples: Windows, macOS, Linux, ChromeOS, iOS, Android.

Application software examples: word processors, spreadsheets, browsers, email, presentation tools, photo editors, games. Productivity suites (Microsoft 365, Google Workspace) bundle them.

File management: files live in folders (directories) in a tree. The path shows where a file is (Documents/INT1010/hardware.docx). Good names and folders make files findable.

File extensions tell the type: .docx (Word), .xlsx (Excel), .pptx (PowerPoint), .pdf, .jpg/.png (images), .mp4 (video), .zip (compressed). Canvas needs the actual file, so know your extensions.

Back up your work: a copy in a second place (cloud drive or USB). One copy is zero copies.

Spreadsheets (Excel): a grid of rows (numbers) and columns (letters). A cell is named by column then row — C4 is column C, row 4. A range is a block of cells — A1:A10.

Formulas start with = and do math: =A1+B1, =A1*2. Functions are built-in formulas: =SUM(A1:A10), =AVERAGE(B2:B20), =MAX(...), =MIN(...), =COUNT(...).

Relative reference (A1) changes when you copy a formula down; absolute reference ($A$1) stays fixed. Sort and filter organize data; charts turn numbers into pictures.

Software licensing: commercial (you pay), subscription/SaaS (you pay monthly, it runs in the cloud), freeware (free to use), open source (free and the code is public), trial/shareware.

Module 4 items: File Management Assignment (50), Excel Assignment (50), and Module 4 Quiz (20) — 120 points.

Worked examples

Example 1: On the board: A1=80, A2=90, A3=70. Write the formula for the average, the highest score, and the total. — =AVERAGE(A1:A3) → 80. =MAX(A1:A3) → 90. =SUM(A1:A3) → 240. Every formula starts with =.

Example 2: A student saves 'essay' to the desktop, then 'essay(1)', then 'final essay real'. Two weeks later they can't find the right one. What went wrong and what should the folder structure be? — No folders, no naming rule, no backup. Fix: Documents/INT1010/Module4/essay-v1.docx, v2…; one folder per module; a copy in a cloud drive.

Example 3: Which is the OS and which is the application: Windows 11, Excel, ChromeOS, Chrome browser, Android, Instagram? — OS: Windows 11, ChromeOS, Android. Applications: Excel, Chrome browser, Instagram. The OS runs the device; apps run on the OS.

Common mistakes

"The Chrome browser is the operating system." Chrome browser is application software; ChromeOS, Windows 11, and Android are operating systems. The OS runs the device; apps run on the OS.
"A formula works without the equals sign." Formulas start with =. Without it, =SUM(A1:A10) is just text in the cell.
"Saving to the desktop is a backup." A backup is a second copy in a second place (cloud drive or USB). One copy is zero copies.

Self-check

Try each one before you look. A miss here costs nothing and tells you exactly what to reread.

1. Which type of software manages the computer's hardware and lets other programs run?

2. Which of these is application software?

3. A file is named report.xlsx. What does the .xlsx extension tell you?

4. Which practice is the best way to keep files organized on a computer?

5. In Excel, which formula adds the values in cells A1 through A5?

Canvas is the official record. This companion enhances the PGCC curriculum; it does not replace it. Last name and class year only. Students with a 504 plan or IEP: your accommodations apply.

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