The first round of fundraising is called the seed round. Once the start-up has raised money in the seed round, they'll hire employees, get the equipment and office space they need, and get to work building the company, developing the product, and making sales.
As they grow, the goal is to raise more money in future funding rounds until the company is large enough to go public or get acquired, allowing early investors, like VC firms, to cash out and exit.
Can you invest in a start-up?
If you're not a professional investor or connected with a VC group or a similar organization, investing in start-ups is generally difficult. Privately held companies typically only have a handful of investors, and retail investors usually have to wait for the IPO to invest in these companies.