To normal everyday people, they're the same thing and I've used both terms regardless.
Anyway, enough semantics for one night, no wonder the public has no trust in its institutions anymore.
They are completely different things and are provided for as separate sections under the Theft Act 1968.
Robbery (which is frequently misattributed by the uninformed) is theft with the application of force (or threat of force) and carries a maximum sentence of life imprisonment.
Burglary (of a dwelling) is where someone enters a dwelling as a trespasser with the intention to steal, which carries a maximum sentence of 14 years, or life if they go tooled up.
They are completely distinct offences, although there is frequently crossover, such as where a robbery in the home (an especially horrible crime) takes place.
In all instances people are allowed to defend themselves to a reasonable extent, based on the circumstances and clearly a home invasion that included weapons would allow for a far more robust response than an opportunistic, unequipped burglar taking his chances.
The problem with your ‘anything goes’ approach is that it would (for example) permit the torture for weeks on end of a twelve year old who had sneaked in through an open door, without any potential consequences for the homeowner. It would also mean leaving man-traps was perfectly acceptable, even though it could maim and kill children who are simply trespassing on a property (as we all did as kids).
Your approach is ill-conceived and not properly thought through and therefore wholly wrong. The law in this regard works very well and is there for good reason, flowing from long established case law and legislation.
These types of prosecutions are very rare for good reason. Juries are very slow to convict anyone whose home has been unlawfully invaded and the CPS will only prosecute someone in those circumstances in the most extreme and unusual of cases. On the face of it, this is one such case, although as ever, it will be for a jury of members of the public to determine anyone’s guilt, based on what they view as reasonable force to defend one’s home in the circumstances.
There has to be a line somewhere. Surely you must accept that? Or do you think it’s fine to torture children?