It will be illegal for anyone currently aged 15 or under to ever buy cigarettes in the UK, under new laws proposed by the government.
The plan is part of a series of measures aimed at tackling the health effects of smoking, one of the UK's leading causes of preventable death, disability and ill-health.
Although smoking rates have fallen, millions of people still do so.
As well as creating a smoke-free generation, the government's Tobacco and Vapes Bill will extend the current indoor smoking ban to some outdoor settings.
Smoking would not be allowed in children's playgrounds and outside schools and hospitals in England. There is little detail on how that would be policed.
Health Secretary Wes Streeting said there would be a "genuine consultation" on the measures following the passage of the bill through Parliament.
However, smoking will not be banned in pub gardens, as had been suggested.
Under the bill, shops will need a licence to sell tobacco, vape and nicotine products in England, Wales and Northern Ireland. Scotland already has a retailers' registration scheme.
The plans have been welcomed by health charities.
Similar anti-smoking proposals brought forward by the previous Conservative government were abandoned ahead of the July 2024 general election.
Under the proposals, outdoor vaping may also be restricted in smoke-free places. However, some health experts are warning such a move would send a confusing message.
Vape advertising and sponsorship will be outlawed, and the government will be able to restrict the flavours, display and packaging of all types of vapes and other nicotine products.
Separately, the government has already said that single-use disposable vapes will be banned in England and Wales from June 2025. Scotland and Northern Ireland are expected to follow suit.
A new tax will also be introduced on vapes containing nicotine from 1 October 2026.
Smoking puts enormous pressure on the NHS. It kills about 80,000 people a year, and is responsible for one in four of all deaths from cancer.
It is also linked to other serious conditions, including heart disease, stroke, type 2 diabetes, asthma and dementia. It can affect fertility and pregnancy.
Figures from NHS England show there were an estimated 408,000 hospital admissions due to smoking in 2022-2023, up from 389,000 in 2021-2022.
Cigarettes release thousands of different chemicals when they burn, including carbon monoxide, lead and ammonia.
Many components of tobacco are poisonous, and up to 70 cause cancer.
Vaping is not as harmful as smoking cigarettes, and the NHS says it has helped thousands of people to quit.
However, health experts warn that anyone who does not currently smoke should not start vaping, because it can cause long-term damage to young people's lungs, hearts and brains.
In December 2023, the World Health Organization (WHO) warned that "alarming evidence" about the dangers of vaping was growing.
Smoking rates among UK adults have been falling.
In 2011, 20% of UK adults smoked, according to the Office for National Statistics (ONS).
But in 2023, just under 12% - six million people - did so.
Fewer than one in 10 young adults in the UK smoked cigarettes in 2023 - down from a quarter of 18-24-year-olds 12 years earlier.
In April 2024, separate research from University College London suggested the proportion of middle class and wealthier women under the age of 45 who smoked had increased in England.
The percentage of women in this group who smoked rose from 12% to 15% between 2013-2023.
Dr Sarah Jackson, who worked on the study, said this could be because this group were less affected by sharp increases in cigarette prices.
An earlier survey of nearly 6,000 people in England found that while half of those who had tried to stop had done so for health reasons, a quarter said it was due to the cost.
As smoking rates have fallen, the use of vapes has risen, with about 5.1 million people using a vape or e-cigarette in 2023.
The ONS says 5.9% of people aged 16 and over vaped every day, up slightly from the previous year, while another 3.9% did so occasionally.
The group with the highest rate of vape use - nearly 16% - was 16-24 year-olds. But the biggest increase in vape use since 2022 was seen among 25-34-year-olds.
Research published in The Lancet in October 2024 found that just over a million people in England vape despite never having smoked regularly.
In 2021, just one in 200 people did so, but by April 2024 this figure had risen to one in 28.
The UK's approach is thought to have been inspired by a policy in New Zealand.
The country's previous government planned to ban anyone born after 2008 from buying cigarettes or tobacco products in their lifetime.
But, in November 2023, the current government said it will scrap the law to help fund tax cuts.
Mexico has some of the strictest anti-smoking laws in the world, including smoking bans at beaches, parks and, in some cases, private homes.
Portugal aims to have a "smoke-free generation" by 2040 and wants to pass a law that would stop bars, cafes and petrol stations from selling tobacco products.
Canada is hoping to reduce tobacco use to less than 5% by 2035. In August 2023, it said manufacturers would have to print health warnings on individual cigarettes.