Metal might seem like a truly commonplace kind of substance in the world of today, but suffice it to say that just a few thousand years ago it was a very difficult material for anyone to end up working with any way, shape or form. You might not think that a few thousand years is all that recent, but bear in mind that human beings have been around for hundreds of thousands of years, and for the vast majority of our existence on this planet we have not been able to use all that much metal at any given point in time.
A big part of the reason why that is the case has to do with the fact that it was previously really impossible for us to melt metal and turn it into a workable enough substance, but the great thing about living in this modern day and age is that there are things like the welding industry that allow us to take advantage of metal and all of the benefits that it can send our way. Technology has affected welding by enabling us to generate temperatures that make welding an actual possibility in the first place, and you might want to take that into account the next time you use a metal based item in your day to day life.
Technology has improved both the heat levels that we can generate in order to melt and conjoin two pieces of metal and it has also vastly increased the precision with which this can be done. Anything that you buy that is welded is the byproduct of many centuries of progress which you should definitely be really grateful for.