Need clarification about certain terms used to do with compiling C files

I am learning C with the GCC compiler and Geany (Arch Linux, if it makes a difference). However, I am seeing the words compile and build used interchangeably, both in Geany and on the internet. I am asking for clarification that the way I understand the compiling process is correct, because Googling it is just making me more confused.

Say I write a simple helloworld.c file:

#include <stdio.h>
int main(void)
{
    printf("Hello world!");
    return 0;
}

If I run gcc -c helloworld.c, the compiler produces a helloworld.o object file. Geany calls this process compilation and the compiler says Compilation finished successfully.

Now, if I run gcc -o helloworld helloworld.c, the compiler produces an executable file called helloworld and Geany calls it building. However, the compiler again says Compilation finished successfully.

I understand that the -c option produces an object file, and that multiple of these can be linked together with libraries to produce an executable file, but I am confused about which scenario is compilation and which is building.

Furthermore, if I had just one source file in the project, such as a single helloworld.c file, is gcc -o helloworld helloworld.c enough to turn the source code into an executable?

Thanks

Solution

To answer your 2nd question: yes, gcc -o myprog myprog.c is just fine. So is gcc -o myprog *.c or gcc -o myprog foo.c bar.c baz.c.

To answer your first question: technically speaking, there's no word as 'building' :) However, the word 'building' and 'compiling' can be used interchangeably to describe the whole process of producing a final executable from source code.

In a more precise context you would say there is:

preprocessing, when the preprocessor includes header files, expands macros, etc.
parsing, where the parser tokenizes the source text and produces a structured data model (a so-called Abstract Syntax Tree) of the program flow.
compiling or compilation, when a code generator traverses the AST and generates assembly code from it
assembling, when the compiler driver invokes an assembler program which turns the assembly text into binary object code and finally
linking or linkage, when the compiler driver invokes a linker to look up symbols in libraries, fill in missing addresses, etc.

So, strictly speaking, only the 3rd small step is the compilation; furthermore, using the GNU toolchain and make, people tend to call the first four steps (producing an object file from a .c source file) compilation as one.