What is the difference between similar instructions: CREATE and INSERT, UPSERT and INSERT with UPDATE, RELATE and INSERT RELATION?

[Be3y4uu-K0T]

Good afternoon, I tried to read the documentation, but I still can't understand the difference of some designs!

Here are the sample queries and I don't see the difference between: #1 and #2; #3 and #4; #5 and #6.
Where, when and what is better to use? And why is there an INSERT that can do 3 things in 1?

Queries:

-- INSERT DATA
-- #1
CREATE users SET name = 'John Doe 1', age = 30;
CREATE users:john SET name = 'John Doe 2', age = 30;
CREATE users:john SET name = 'John Doe 3', age = 30;

-- #2
INSERT INTO users { name: 'Jane Doe 4', age: 28 };
INSERT INTO users { id: 'john2', name: 'Jane Doe 5', age: 28 };
INSERT INTO users { id: 'john2', name: 'Jane Doe 6', age: 28 };

-- INSERT OR UPDATE DATA
-- #3
UPSERT users SET name = 'John Doe 7', age = 30; -- Query 7 - why does it update, although according to the documentation it should only do an insert?
UPSERT users:john SET name = 'John Doe 8', age = 30;
UPSERT users:john SET name = 'John Doe 9', age = 30;

-- #4
INSERT INTO users { name: 'Jane Doe 10', age: 28 }
    ON DUPLICATE KEY UPDATE name ='Jane Doe 11', age = 28;
INSERT INTO users { id: 'john', name: 'Jane Doe 12', age: 28 }
    ON DUPLICATE KEY UPDATE name ='Jane Doe 13', age = 28;
INSERT INTO users { id: 'john', name: 'Jane Doe 14', age: 28 }
    ON DUPLICATE KEY UPDATE name ='Jane Doe 15', age = 28;

-- RELATE DATA
-- #5
RELATE users:john->friend->users:john2
    SET data = '1';

-- #6
INSERT RELATION INTO friend {
	in: users:john,
	out: users:john2,
    data: '1'
};

-- SELECT DATA
-- #7
SELECT * FROM users;
SELECT * FROM friend;

Results:

-------- Query 1 (1ms) --------

[
	{
		age: 30,
		id: users:yo70gme4alhka6f9ao62,
		name: 'John Doe 1'
	}
]

-------- Query 2 (0ns) --------

[
	{
		age: 30,
		id: users:john,
		name: 'John Doe 2'
	}
]

-------- Query 3 (1ms) --------

'Database record `users:john` already exists'

-------- Query 4 (0ns) --------

[
	{
		age: 28,
		id: users:a0r9ocbry3h07hrhb0pf,
		name: 'Jane Doe 4'
	}
]

-------- Query 5 (0ns) --------

[
	{
		age: 28,
		id: users:john2,
		name: 'Jane Doe 5'
	}
]

-------- Query 6 (0ns) --------

'Database record `users:john2` already exists'

-------- Query 7 (1ms) --------

[
	{
		age: 30,
		id: users:a0r9ocbry3h07hrhb0pf,
		name: 'John Doe 7'
	},
	{
		age: 30,
		id: users:john,
		name: 'John Doe 7'
	},
	{
		age: 30,
		id: users:john2,
		name: 'John Doe 7'
	},
	{
		age: 30,
		id: users:yo70gme4alhka6f9ao62,
		name: 'John Doe 7'
	}
]

-------- Query 8 (0ns) --------

[
	{
		age: 30,
		id: users:john,
		name: 'John Doe 8'
	}
]

-------- Query 9 (0ns) --------

[
	{
		age: 30,
		id: users:john,
		name: 'John Doe 9'
	}
]

-------- Query 10 (1ms) --------

[
	{
		age: 28,
		id: users:3oprv0gf3j49l6gkjtjh,
		name: 'Jane Doe 10'
	}
]

-------- Query 11 (0ns) --------

[
	{
		age: 28,
		id: users:john,
		name: 'Jane Doe 13'
	}
]

-------- Query 12 (0ns) --------

[
	{
		age: 28,
		id: users:john,
		name: 'Jane Doe 15'
	}
]

-------- Query 13 (0ns) --------

[
	{
		data: '1',
		id: friend:fafcpzgpblvcmvb8bc6f,
		in: users:john,
		out: users:john2
	}
]

-------- Query 14 (0ns) --------

[
	{
		data: '1',
		id: friend:nnif626xixkp8rwm28gx,
		in: users:john,
		out: users:john2
	}
]

-------- Query 15 (1ms) --------

[
	{
		age: 28,
		id: users:3oprv0gf3j49l6gkjtjh,
		name: 'Jane Doe 10'
	},
	{
		age: 30,
		id: users:a0r9ocbry3h07hrhb0pf,
		name: 'John Doe 7'
	},
	{
		age: 28,
		id: users:john,
		name: 'Jane Doe 15'
	},
	{
		age: 30,
		id: users:john2,
		name: 'John Doe 7'
	},
	{
		age: 30,
		id: users:yo70gme4alhka6f9ao62,
		name: 'John Doe 7'
	}
]

-------- Query 16 (0ns) --------

[
	{
		data: '1',
		id: friend:fafcpzgpblvcmvb8bc6f,
		in: users:john,
		out: users:john2
	},
	{
		data: '1',
		id: friend:nnif626xixkp8rwm28gx,
		in: users:john,
		out: users:john2
	}
]

SurrealDB version:

$ surreal version
2.1.0 for macos on aarch64

P.S.: Apologies, English isn't my first language.