Drawing 3 circle (diagram) in Latex

Question

I am relatively new to diagram in latex.

Basically, I want to draw a diagram as shown below. It does not be exact same, but around that content.

\usepackage{tikz}
\begin{tikzpicture}

\draw (2,2) circle (3cm);

\end{tikzpicture}

enter link description here

Answer 1

None of this is difficult and most of the things have already been done somewhere. So all you need to do is to google and to patch the pieces from here and there together. The ring shading is from here, the fancy arrow is from here and the rest is from the pgf manual.

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{decorations.pathreplacing,calc} 
\makeatletter%https://tex.stackexchange.com/a/82432
\pgfdeclareradialshading[tikz@ball]{ring}{\pgfpoint{0cm}{0cm}}%
{rgb(0cm)=(1,1,1);
rgb(0.719cm)=(1,1,1);
rgb(0.72cm)=(1,1,1);
color(0.9cm)=(tikz@ball!60)}
\tikzoption{ring color}{\pgfutil@colorlet{tikz@ball}{#1}\def\tikz@shading{ring}\tikz@addmode{\tikz@mode@shadetrue}}
\makeatother
\begin{document}
\begin{tikzpicture}[fancy arrow/.style={decorate,decoration={ % https://tex.stackexchange.com/a/500018
 show path construction, 
 curveto code={ 
 \draw[top color=blue!30,bottom color=blue] 
 let \p1=($(\tikzinputsegmentsupporta)-(\tikzinputsegmentfirst)$) in 
 [/utils/exec=\pgfmathsetmacro{\mysign}{sign(\x1)}] 
 ([yshift=-3.5pt]\tikzinputsegmentfirst) .. controls 
 ([yshift=-3.5pt]\tikzinputsegmentsupporta) and ([yshift=-3.5pt]\tikzinputsegmentsupportb) 
 ..([yshift=-3.5pt,xshift=\mysign*3pt]\tikzinputsegmentlast) 
 -- ([yshift=-3.5pt,xshift=\mysign*3.5pt]\tikzinputsegmentlast) 
 -- ([yshift=-5.5pt,xshift=\mysign*3.5pt]\tikzinputsegmentlast) 
 -- (\tikzinputsegmentlast) 
 -- ([yshift=5.5pt,xshift=\mysign*3.5pt]\tikzinputsegmentlast) 
 -- ([yshift=3.5pt,xshift=\mysign*3.5pt]\tikzinputsegmentlast) 
 .. controls 
 ([yshift=3.5pt]\tikzinputsegmentsupportb) and ([yshift=3.5pt]\tikzinputsegmentsupporta) 
 .. ([yshift=3.5pt]\tikzinputsegmentfirst) -- cycle;}}},
 pics/fancy circle/.style={code={
 \path[even odd rule,fill=#1!60,path picture={
 \draw[line width=6mm,#1!20] ([yshift=3mm]path picture bounding box.west)
 to[out=-20,in=-120] ([xshift=5mm]path picture bounding box.north);
 }]  
 circle[radius=\pgfkeysvalueof{/tikz/fancy circle/radius}] 
 circle[radius=0.8*\pgfkeysvalueof{/tikz/fancy circle/radius}];
 \path[even odd rule,ring color=#1] 
  circle[radius=0.8*\pgfkeysvalueof{/tikz/fancy circle/radius}]
  circle[radius=0.8*\pgfkeysvalueof{/tikz/fancy circle/radius}-1mm];}},
 fancy circle/radius/.initial=1.55cm,
 pics/arr/.style={code={\draw[#1,top color=#1!20,bottom color=#1]
 (45:0.5) -- ++ (0.3,0) -- ++ (-45:0.5) -- ++(-135:0.5) --++ (-0.3,0)
 -- ++ (45:0.5) -- cycle;}}] 
%
 \path(-4,0) pic{fancy circle=blue} node[font=\large\sffamily]{AAA} 
  (-2.7,0) pic{arr=blue}
  (0,0) pic{fancy circle=purple} node[font=\sffamily]{Transformation} 
  (1.3,0) pic{arr=purple}
  (4,0) pic{fancy circle=orange} node[font=\large\sffamily]{AAA} ;
 \path (0,-2.5) node[top color=white,bottom color=green!30,rounded
  corners=3pt,draw=green!40,font=\sffamily\Large,minimum height=1cm,
  minimum width=2cm](H) {HUMAN};
 \draw[fancy arrow] (H.east) to[out=0,in=0,looseness=1.5]++(0,1);
 \draw[fancy arrow] ([yshift=1cm]H.west)
  to[out=180,in=180,looseness=1.5] (H.west);
\end{tikzpicture}
\end{document}