XARGS Madness

Have been trying to understand the working of xargs for quite sometime now.Can someone help me understand and give me some sample code that will help me practise.

The following is what I have tried but could not get the output
find <directory name> - name "*.txt" -print | xargs grep <pattern> | tee <file_name>

this is a simple program
the output of the command preceding is passed line by line to the command following xargs
[335802@oracleclient ~]$ cat>datadata
data1
data2

[1]+ Stopped cat > datadata
[335802@oracleclient ~]$ cat>data1
data1
hello1

[2]+ Stopped cat > data1
[335802@oracleclient ~]$ cat>data2
data2
hello2

[3]+ Stopped cat > data2
[335802@oracleclient ~]$ cat datadata | xargs cat
data1
hello1

data2
hello2

For example, take this example

Code:

ls *.txt | xargs cat

ls *.txt ll return all files with txt extension. each filename is given as input to cat because of xargs. (this command displays contents of all the txt files)

find <directory name> - name "*.txt" -print

the above line lists all the .txt files in that particular directory.

| symbol passes the output of the above code to the command on the right

xargs grep <pattern>

in this xargs does the job of taking in multiple arguements(which is actually a list) and performs the grep function

[335802@oracleclient ~]$ cat>y.txt
12345
34567

[5]+ Stopped cat > y.txt
[335802@oracleclient ~]$ cat>y1.txt
123
abc
def

[6]+ Stopped cat > y1.txt
[335802@oracleclient ~]$ cat>y12.txt
andfff
dfree

[7]+ Stopped cat > y12.txt
[335802@oracleclient ~]$ find ./ -name "y*" -type f -print | xargs grep "123tee hg.txt
./y.txt:12345
./y1.txt:123
[335802@oracleclient ~]$ find ./ -name "y*" -type f -print | xargs grep "a" e hg.txt
./y12.txt:andfff
./y1.txt:abc