Imagine you’re making a cake.
After mixing various ingredients, cooking the batter, you’ve now baked a yellow cake.
Suddenly, you wish it were pink.
Instead of making an entirely new cake you choose an easy solution by taking water and pink food coloring and spraying the cake to turn it pink.
However, maybe tomorrow at your party when someone asks you to cut the cake and finds the interior still yellow that will cost you not just the time it took to spray the cake pink but now the rework to make a new entirely pink cake.
This is similar to technical debt; the cost of additional rework caused by choosing an easy (limited) solution now instead of using a better approach that would take longer.
Note that technical debt is not always a negative and can be helpful to serve as a proof-of-concept.
However a risk is that when unpaid it can accumulate ‘interest’. This is known as software entropy, where changing existing software will result in unexpected problems.
A change in the database often impacts other parts of the codebase or documentation that need to be changed.
Circling back to our backing analogy this could be the impact of how making a new pink cake will also mean that food coloring needs to be added to the recipe and new photos of the cake need to be updated on the website.