I have a few simplistic code confusions

First question:

Say we have:

a : STD_LOGIC_VECTOR(0 TO 4);

b : STD_LOGIC_VECTOR(2 TO 6);

b <= "10100";

a <= b;

How do the bits get assigned to "a" here?

Does it go like this:

b ---------------- a

bit2 -- goes to -- bit0

bit3 -- goes to -- bit1

bit4 -- goes to -- bit2

bit5 -- goes to -- bit3

bit6 -- goes to -- bit4

Likewise:

Say we have:

a : STD_LOGIC_VECTOR(2 DOWNTO 0);

b : STD_LOGIC_VECTOR(2 TO 9);

b <= "10100110";

a(2 DOWNTO 1) <= b(5 TO 6);

How do the bits get assigned to "a" here?

Does it go like this:

b ---------------- a

bit5 -- goes to -- bit2

bit6 -- goes to -- bit1

Second question:

When I'm looking at something like this, this is a logic gate/construct right?

b <= NOT(v) OR w OR (NOT(x) AND NOT(y) AND NOT(z));

I would just look at this in the same way as a logic diagram right? If NOTv is high OR w is high OR NOTx AND NOTy AND NOTz is high (all three), then b will be given a high?