Processes normally have separate address spaces; threads within a process share substantial memory and resources. Isolation and communication cost differ.
Before you start
You should understand processes, threads, memory and basic file operations. Track ownership and state changes over time. For concurrent scenarios, write down at least two possible execution orders; the same instructions can behave differently when scheduling or resource availability changes.
The practical goal is to reason through this situation: Two threads can access one shared object, while processes need an explicit communication mechanism. Read the walkthrough first, then try the interview exercise before opening its answer. The important part is explaining the decision and its consequences, rather than remembering a definition alone.
Step-by-step walkthrough
Step 1: Identify isolation needs
Separate processes normally have separate address spaces.
Step 2: Identify shared ownership
Threads share memory and need coordination for mutable state.
Step 3: Compare failure and transfer
Communication cost and failure scope affect the appropriate boundary.
Worked scenario
Two threads can access one shared object, while processes need an explicit communication mechanism.
Two threads update one in-process cache easily but can race over its entries. Two processes need an explicit transfer or shared-memory arrangement, giving stronger ordinary address-space separation but additional communication design. Neither choice alone establishes safe access to files or external services shared by both.
Common mistake
Shared memory convenience introduces races and does not guarantee coordinated access.
Verify the behavior
Trace shared data and failure impact under both proposed boundaries.
Interview exercise
Choose a task boundary.
Answer and reasoning
Compare isolation needs, communication frequency and failure impact before selecting threads or separate processes.
Continue learning
Compare the scenario with the Operating Systems interview questions and test your understanding with the Operating Systems MCQs. For terminology and implementation details, consult the reference material.