A smart city conjures up futuristic images of flying cars, Iron Man-style costumes and hi-tech holographic communication devices. But in reality it means using technology to make cities work better and so attract smart people.
Three of the best-known smart cities are Denver and Austen in the US and Yinchuan in China. Some African cities are now making their mark.
Smart cities, according to Nico Venter, an associate director for cities at Arup in Southern Africa,are about "making cities faster, efficient and cheaper", but this requires co-ordination from the government, municipalities and tech developers to make it work for all residents.
He said each city needed to understand what its competitive advantage was and from there define what smart meant for it. "It is understanding how it can attract further investment, talent and development and aligning it to the direction they want to go ."
Cape Town is ranked 22nd out of 22 cities in the Savills Tech Cities 2017 report, released this week, for being a standout tech city in Africa.
The rankings measure the business and technical environment, city buzz, residents' wellness, talent pool and property costs. Cape Town was also ranked as the second-cheapest city in terms of cost of living.
The Mother City also ranked high - on a par with Johannesburg - in the 2016 Frost & Sullivan Smart Cities report, particularly in the smart citizens category, which measures the level of internet connectivity and access to information among residents.
Boosting its standing in connectivity is its Smart Cape initiative - aimed at encouraging young people to make use of the internet and expand their skills. It has more than 300000 registered users.
Also helping the city's ranking is that it installed energy-efficient lighting in government buildings and traffic lights. Mauritz Venter, a research analyst at Frost & Sullivan, said the city expected to save R120-million by 2018 from the project.
Last year, Cape Town launched ShotSpotter in areas where there are gangs. "Every time a gunshot is fired, these devices will pick up the gunshot in real time and send that information to local authorities immediately," he said.
The data tells the police how many guns were fired, the number of shots, where the shooting took place - within a metre - and at what time.
Globally, cities are investing in technology that will capitalise on the growth in connected devices - the Internet of Things.
Last year, Denver, in Colorado, announced a partnership with Panasonic to create the first phase of Peña Station.
The station is a 160ha transport hub that will have its own micro electricity grid using stored solar power, LED streetlights with high-definition security cameras, and video surveillance on parking meters that can recognise car number plates, detect vacant parking spaces and offer directions to them. The meters will accept credit cards and digital payments.
The station also has Wi-Fi, electric vehicle charging stations and autonomous electric shuttles.
With Africa's accelerating urbanisation, major economic hubs face the challenge of integrating smart technology with infrastructure while housing a swelling population.
According to the 2016 Africa Outlook Report compiled by the African Development Bank, Africa will have 760million urban residents by 2030.
This is expected to increase to 1.2billion by 2050, most of them between the ages of 18 and 35.
Sharon Peetz, mayoral committee member for economic development in Johannesburg, speaking this week at the Global Entrepreneurship Summit, said African cities were urbanising faster than in any other region of the world and were increasingly seen as "centres of hope".
Johannesburg receives at least 10000 people a month. Of these, "30% come from the rest of Africa. But in order for us to trade as a global city, we need foreign nationals who bring in their skills, which are important for driving the economy."
Julius Muia, director-general of Kenya Vision 2030, said that about a third of Kenya's population lived in urban areas.
Muia said African governments were building cities to accommodate the influx.
"Cities of the future are going to be planned cities. We will use technology and the expertise that we have. We will be seeing smart cities, carbon-neutral cities and water-neutral cities because water is going to be a challenge ."
Muia said the size of the cities meant they would be the main socioeconomic and political drivers of agendas, which meant tackling how cities were planned and what role they would play in the economy.
Arup's Nico Venter said Africa did not have the luxury of time to go through the process of industrialisation like Western cities had.
"We can use the tools of technology in a smart manner to leapfrog that gap," he said.
Johannesburg's fast and somewhat haphazard development into an economically and culturally charged metropolis points to the importance of the planning Muia is referring to.
Johannesburg - known sometimes as Johustlersburg because its residents are constantly looking for their next break - is South Africa's business hub and a city focused on productivity and career growth. This has earned it a high ranking as one of Frost & Sullivan's cities with smart citizens.
But it wasn't always the case.
When Olitzki Property Holdings founder Gerald Olitzki developed a plan for Gandhi Square in the early 1980s, it was never his intention to work his way into the rest of the city.
But because people flocked to the city for jobs, he saw the urgent need for the redevelopment of the CBD.
"This is a mining town we live in; it was never planned ... although the city had to a certain extent died, there were all these people coming to work, coming to Absa and Standard Bank," said Olitzki.
His company partnered with banks and mining companies such as Anglo American to establish safe zones with walkways where there was security, landscaping and lighting.
Transport initiatives also made Johannesburg a top African city in Frost & Sullivan's report, because of the Gautrain and Rea Vaya bus system. "That was bolstered by the fact that the buses are energy efficient, so Joburg did well in terms of improving transport and keeping it clean," said Frost & Sullivan's Mauritz Venter.
Apps such as uGoMyWay - designed to encourage people travelling the same route to ride together - could help ease traffic congestion, he said.
The solution to traffic congestion is not always more roads . Arup's Venter said a smart city would use existing infrastructure and technology to create more effective transport systems which offer the potential to integrate the formal and informal networks, thus optimising the use of existing infrastructure.
Yet, despite the investment in city infrastructure, Olitzki said: "My difficulty in South Africa is that if it is not driven by private enterprise, it won't work."
Speaking on the advancements of other global cities, he said: "There may be a level of sophistication to that which we [South Africans] are not quite ready for, but it's a progression; we start off at the lowest level and we start building up and building.
"As far as technology is concerned, it's a process. It's not an overnight wonder."