bike bits - braze-ons, water bottles
Braze-ons are the lugs for bolting on various components to the bike: racks, mudguards, (that’s fenders), water bottle cages, etc.
Specialised touring bikes seem to have them all over, carefully thought through to give plenty of flexibility to component choice.
Mountain bikes, you are not so lucky.
Suspension forks often have none, meaning fitting a front rack needs a specialised fixing method. (They are around.) Don’t be put off bunging on a front mudguard though. Use hose clamps to fix the support to the fork.
Actually those hose clamps come in useful for fixing a lot of things to the bike even if there’s no appropriate braze-on.
Just need some lateral thinking.