Ministers briefed the media on Wednesday - just over 24 hours before nationwide lockdown - to give clarity on what is allowed or not allowed during the lockdown, and to explain how basic services will function.
Here's what you need to know:
There will be no non-essential movement
Police Minister Bheki Cele warned of consequences for those who attempt to leave their homes, unless for essential purposes, such as buying groceries, seeking medical attention, collecting grants, buying medication, or emergencies.
Cele also ruled out dog-walking and jogging, contradicting Health Minister Zweli Mkhize's comments earlier on Wednesday.
He said the security cluster discussed the matter and concluded that these activities were against the principle of the lockdown.
Gatherings will be banned, except for funerals, which must be attended by 50 people or less.
Movement between provinces, metros and district areas will also be banned and roadblocks on community, provincial and national roads will be conducted to enforce this.
At these roadblocks, particularly between provinces, health officials will screen people and police will ensure movement is restricted.
Restrictions exclude essential services staff, such as healthcare workers, emergency services officials, service delivery personnel and police.
There will be no cross-border trips during the lockdown, with the exception of essential goods and cargo.
Minibus taxis, metered taxis and e-hailing services will be limited to the public during the lockdown, Transport Minister Fikile Mbalula said.
Only staff rendering essential services and those out for essential purposes, such as buying groceries or going to work, will be allowed to leave home.
Taxis will only be allowed to transport people for these essential trips from 05:00 to 09:00 and 16:00 to 20:00.
A vehicle licensed to carry up to four people, will only be permitted to load one person. A vehicle licensed to carry up to eight passengers will only be permitted to load a maximum of three passengers.
Buses will also have limited operations - only transporting essential services workers and people making necessary trips.
Mbalula added that courier services would only be allowed for essential goods.
Liquor sales and groceries
Cele stressed that the sale and purchase of liquor would be prohibited at all shops.
Shops will also only be able to sell essential food and goods while non-essential items, such as clothing, will be prohibited, according to Minister of Trade and Industry Ebrahim Patel.
Any place that does not sell essential goods and services will be closed.
Public and private facilities will be closed
Many places, such as parks, beaches, public swimming pools, nightclubs, casinos, game reserves, resorts, hotels, lodges, guest houses (except when they are required for remaining tourists), restaurants, shebeens, taverns, theatres, cinemas and shopping malls will be closed.
No driver's licence renewals
Mbalula said vehicle testing centres and drivers' licence testing centres would be closed during the lockdown.
Should your driver's licence expire during this time, it will remain valid for the duration of the lockdown and a 14-day grace period will be given thereafter.
Violence against women and children
Social Development Minister Lindiwe Zulu and Cele explained that mechanisms for those who felt unsafe in their homes during the lockdown were put in place.
A hotline has been set up for the gender-based violence command centre. Victims can call 0800 428 428 for assistance.
Shelters will remain functional, including old age homes, child and youth care centres and rehabilitation centres.
Cele said there was a possibility of an escalation in gender-based violence during this period and added that the police's Family Violence, Child Protection and Sexual Offences unit was beefed up.
Victims can call 0800 150 150 for an urgent response.
People are still able to report crimes because the 10111 emergency line will still be operational during the lockdown.
Although the police and the South African National Defence Force (SANDF) will be on foot patrols, people can also report contraventions of lockdown regulations.
The government will have to discuss whether parents who share custody will be allowed to drop off their children, Zulu said.
But she appealed to parents to think carefully about their children and their risk of exposure, suggesting that they arrange for the children to stay in one place for the 21-day period and make use of available communication tools.
Home Affairs documents
Home Affairs Minister Aaron Motsoaledi said only replacement IDs, birth certificates and death certificates would be issued during the lockdown.
No visas, marriage certificates or any other document will be issued until after the lockdown.
Grant payments still available
South Africans will still be able to access their grant payments.
Older and disabled citizens will be able to access their grants on 30 and 31 March, while all other grants will be available from 1 April.
Stick to the rules
Anyone who contravenes the regulations of the lockdown faces a fine, or jail time for six months or less.