@aimone; it seems that every lockdown is different. Some claim to be tuned to the place being locked down - as with Sydney's southwestern suburbs.
In June 2020 Victoria started what became a long lockdown by applying restrictions only to 'hot spots'. The virus easily spread beyond those however.
As a precaution the Victorian Government imposed a Stage 5 hard lockdown on North Melbourne's huge apartment towers for five days. Meantime the virus spread throughout Melbourne so a more general Stage 3 lockdown was applied to all of Victoria. Still the virus spread so much tougher Stage 4 restrictions were imposed - that worked but it still took a couple of months to undo what had already occurred.
That explains why all Australian states and territories except NSW resolved to lockdown hard and early - that strategy has worked every single time.
Australia's current exception is Greater Sydney - the restrictions imposed are similar to Melbourne's 2020 Stage 3. Unless NSW tightens up it will become Australia's first example of a failure to manage Covid19 - Berejiklian has just one more week before it swamps NSW Health authorities.
