What is TikTok and could the US ban it?

The TikTok video app is hugely popular with young people around the world.

But for many years the Chinese-owned company has faced questions over the security of users' data, and its links to the government in Beijing.

US politicians are debating legislation that would force TikTok's parent company to sell the app, but former US president Donald Trump has criticised the bill, despite previously supporting a ban.

TikTok is a short form video app that, like YouTube, allows people to post, share and comment on videos.

These can range from three seconds to three minutes in length, and users can easily edit their clips using filters, stickers, music and visual effects.

It first shot to popularity as a destination for young people to take part in popular dance or lip-syncing trends and challenges.

Depending on their age and where they live, some users can live stream video content to their followers, as well as support their favourite creators with digital gifts or subscriptions.

TikTok Shop, the platform's dedicated online store, allows users to buy products including those featured in creators' videos.

Since early 2019, TikTok has frequently topped app download charts.

It battled Instagram to be the world's most downloaded app throughout 2023, according to Sensor Tower, which monitors the performance of social media firms.

TikTok is owned by Chinese company ByteDance, which was founded in 2012.

The Beijing-based firm is registered in the Cayman Islands, and has offices across Europe and the US.

It also owns video editing software CapCut, as well as various other apps that are only available in mainland China - including Douyin, a Chinese version of TikTok.

Singaporean entrepreneur Shou Zi Chew is the platform's chief executive officer, although some analysts believe ByteDance founder Zhang Yiming makes many key decisions.

At the heart of TikTok is its algorithm.

This is a set of instructions within the app which determines which content is presented to users, based on data about how they engaged with previous material.

Users are offered three main feeds on their app - Following, Friends and For You.

The Following and Friends feeds present users with content from people they have chosen to follow and who follow them back, but the For You feed is automatically generated by the app.

This curated feed has become the main destination for users hungry for new content, and creators hungry for the millions of views TikTok videos can clock up if they go viral.

Politicians and regulators around the world are worried about TikTok's Chinese owners, despite concerted attempts to persuade them that the app is safe.

Like many other social media apps, TikTok collects data from users, but it has faced additional scrutiny over how much it gathers and who can access it.

In particular critics fear that the information could fall into the hands of the Chinese government - something TikTok and ByteDance have strenuously denied could happen.

TikTok has repeatedly sought to distance itself from its Chinese owners, and has tried to reassure regulators with initiatives such as "Project Clover", which started storing European user data locally.

If successful, it would require ByteDance to sell TikTok within six months, or face a ban from US app stores and web hosting platforms.

President Joe Biden says he will sign the bill into law if it reaches his desk.

It follows previous efforts by American authorities to limit access to the app, citing national security risks.

But Mr Trump - who hopes to be the Republican candidate for the 2024 presidential election - has criticised the new bill, saying limiting TikTok would unfairly benefit Facebook.