I'm sure the thread that PtA linked will go over this somewhere (I haven't read it- too long), but I'll take a crack at the OP and try to be brief:
There seems to be several types of evolution and I was hoping someone could give me a precise meaning when they say 'evolution'. Also, is it compatible within a Christian view, or does it weaken Christianity?
I presume you are talking about (and I could be wrong, so if I am feel free to disregard) what is popularly referred to as "microevolution" and "macroevolution". Microevolution is taken to mean merely changes within a species that do not change the species itself (like the color of wings on a moth, or why we have Golden Retrievers and Chihuahuas, though both are dogs), and macroevolution is usually used interchangeably with speciation.
They are often considered two separate concepts entirely in some Christian circles, and I've known many a Christian to say "I believe in microevolution, not macroevolution."
However, biologists use the terms microevolution and macroevolution to refer to the same process (evolution), with micro and macro distinguishing time. Wikipedia explains this well:
Scientific organizations such as the American Association for the Advancement of Science describe microevolution as small scale change within species, and macroevolution as the formation of new species, but otherwise not being different from microevolution. In macroevolution, an accumulation of microevolutionary changes leads to speciation. The main difference between the two processes is that one occurs within a few generations, whilst the other takes place over thousands of years (i.e. a quantitative difference). Essentially they describe the same process; although evolution beyond the species level results in beginning and ending generations which could not interbreed, the intermediate generations could. Even changes in the number of chromosomes can be accounted for by intermediate stages in which a single chromosome divides in generational stages, or multiple chromosomes fuse. A well documented example is the chromosome difference between humans and great apes. Contrary to the claims of some antievolution proponents, evolution of life forms beyond the species level ("macroevolution", i.e. speciation) has indeed been observed and documented by scientists on numerous occasions.
The difference is quantitative, not qualitative. Hope that helps!