Thread: difference between String Concatenation and String -Buffer/Builder .append(<value>)

in the book that im reading, the difference between concatenation and .append() doesnt explain the difference fully, only by some simple codes and some short statements implies a difference between the two

given the following objects refers to a string value
Concatenation:

strObject = strObject + word;

 
stringBufferObject.append(word);

when i use an output statement(i.e System out), they dont differ too much, in fact they output in the same way, but one thing the book says that, with the use of StringBuffer or StringBuilder object, a program can avoid creating temporary String objects..

its a bit complicated on my part. i need some low level english to understand this part

what is the difference between a basic string concatenation and using .append(<string value>) of String Buffer/Builder object.