Transactions around the world are massively delayed and sometimes even fail completely because the Bitcoin network has reached its capacity.
Usually, the average time to confirm a transaction is 10 minutes but now, because of the issue, this has changed to a whopping 43 minutes.
Bitcoin transactions are confirmed every time miners create a new block on the networks chain. A block contains about 1 MB of information, and it takes about 10 minutes for it to be mined. But right now, there are more than 1MB worth of transactions asking to be confirmed in the 10 minutes that it needs. Many in the Bitcoin community have called for increasing the block size to 2MB but unfortunately this proves to be a highly contentious issue.
Because of that matter, a schism has developed between the team in charge of the original codebase for Bitcoin (Core) and a rival faction pushing its own version of that open source code with a block size increase added in (Classic).
Most of the largest Chinese miners, representing the majority of mining resources, have thus far sided with Core. Anyone can cast a vote for their preferred code by running a Bitcoin node powered by that software.