Public vs private blockchains - Visual Side-by-Side Comparison

Concept Flow - Public vs private blockchains

Start

↓

Choose Blockchain Type

↓

Public Blockchain

↓

Open to Everyone

↓

Decentralized

↓

Consensus by All

↓

Transparent

↓

End

This flow shows the choice between public and private blockchains, highlighting their access, control, consensus, and transparency differences.

Execution Sample

Blockchain / Solidity

blockchain_type = 'public'
if blockchain_type == 'public':
    access = 'open to everyone'
else:
    access = 'restricted access'
print(access)

This code checks the blockchain type and sets access accordingly, then prints the access type.

Execution Table

Step	blockchain_type	Condition	Branch Taken	access	Output
1	'public'	blockchain_type == 'public'	True	open to everyone
2	'public'	else	False		open to everyone

💡 Condition true at Step 1 (if branch taken), else skipped (Step 2), access set and printed, execution ends.

Variable Tracker

Variable	Start	After Step 1	After Step 2	Final
blockchain_type	'public'	'public'	'public'	'public'
access	undefined	'open to everyone'	'open to everyone'	'open to everyone'

Key Moments - 2 Insights

Why does the code choose 'open to everyone' access?

Because the variable blockchain_type is 'public', the condition blockchain_type == 'public' is True at Step 1 in the execution_table, so the code sets access to 'open to everyone'.

What happens if blockchain_type is not 'public'?

The condition at Step 1 becomes False, so the else branch runs (Step 2), setting access to 'restricted access' instead.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of 'access' after Step 1?

A 'open to everyone'

B 'restricted access'

C undefined

D 'public'

💡 Hint

Check the 'access' column in the row for Step 1 in execution_table.

At which step does the else branch run if blockchain_type is 'private'?

A Step 1

B Step 2

C No step, code stops

D Step 3

💡 Hint

Look at the 'Branch Taken' column for the else condition in execution_table.

If blockchain_type changes to 'private', how does the 'access' variable change in variable_tracker?

A It stays 'open to everyone'

B It becomes undefined

C It becomes 'restricted access'

D It becomes 'public'

💡 Hint

Refer to the explanation in key_moments about the else branch and variable_tracker changes.

Concept Snapshot

Public vs Private Blockchains:
- Public: open to everyone, decentralized, consensus by all, transparent.
- Private: restricted access, centralized control, consensus by selected nodes, limited transparency.
- Access control is key difference.
- Code example shows simple access assignment based on type.

Full Transcript

This visual execution compares public and private blockchains by showing a simple code example that sets access based on blockchain type. The flow diagram outlines the decision path from choosing blockchain type to access and consensus differences. The execution table traces the code steps, showing how the condition blockchain_type == 'public' leads to setting access to 'open to everyone'. The variable tracker follows variable changes step by step. Key moments clarify why the code chooses one branch over another. The quiz tests understanding of variable values and branching decisions. The snapshot summarizes the main differences and the code logic.