Universities have huge endowments and investment portfolios. These are generally broad and in support of keeping the financial backing of the school stable; this is extremely prevalent in the large older universities like Harvard or Columbia (but almost all universities have one in some form or another). They support both students and ongoing academic research.

While many of these portfolios consist of wider funds, many have specific investments in specific companies and industries. That means that the university is invested in, and taking benefit from, areas of industry. The main request is to divest the investment portfolios from companies owned by or supporting entities connected with Israel's war on Gaza. In some cases this may be possible (move a ton of stock from a defense contractor making weapons sold to Israel to an energy company) and in some cases it may not (they're invested in a wide market fund that itself invests in specific funds, but you can't easily cherry-pick which stocks are actually in it). It's also possible that there are research grants funded through companies who the students want to apply negative pressure to; cancelling a grant sends a message to the company, but also leaves entire teams and time-dependent science without funding, potentially ending it outright unless alternate funding can be found. There also may be contracts involved for specific research and engagements, and breaking a contract is more complicated than just ripping it up (especially if there are early termination policies outlined).

Realistically, the best students can hope for is a commitment to investigate and divest where possible, which is frustrating but also makes sense. I've worked in higher education for 20 years and have seen this on a smaller scale around defense contractors during the wars in Afghanistan and Iraq. The endowment is a slow moving leviathan, but I think it's a good place for the students to apply pressure.