Evolution question on resistant bacteria

It says in my textbook that because of antibiotics excessive and widespread use bacteria have evolved resistant strains. Doesnt evolution mean change from one species to the next? Or in this context does it simply mean by natural selection the species with the resistant strain would increase,and the others would die?
If it means evolution in terms of changing species, then that would mean that the bacteria have become a different species incapable of having an offspring with each other. Wouldnt it?
I need clarification

First, let's clarify what a specie is, so we're both on the same page. Healthy organisms of a species can breed with each other and give rise to fertile offspring. But organisms of different species cannot produce fertile offspring.

Evolution doesn't necessarily needs to give rise to completely new species, although it is capable of doing so. Evolution is, simply put, the adaptation of a species to a changing environment. It can lead to different species if a group is split off and needs to face different environments, but it is a slow and gradual process.

Now, as for your bacteria:
The bacteria are evolving because the resistant ones are better adapted to their environment, and so they can pass on this resistance. But this is just one change, and it is quite likely that they scan still "reproduce" (bacteria are capable of transferring genetic information!) with the non-resistant ones.

I hope I helped clearing it up. :-)

In the case of bacteria, they don't reproduce with each other anyway. They divide.

Antibiotics kill most of the bacteria, but if some survive chances are it will be the ones with more resistance to the medication. They live, and pass this trait on. If more antibiotics are used and still fail to kill all of them, the absolute most resistant ones still survive and multiply. Eventually this can lead to greater adaptation and a resistant strain of bacteria.