Inside <svg> Can find the following items:
<rect> rectangle
<circle> circle
<ellipse> ellipse
<line> line
<polygon> polygon
<polyline> Polyline
<path> path
<text> text
<linearGradient> linear gradient (transition from one color to another)
<radialGradient> radial gradient (transition from one color to another)
<filter> filter
   <feBlend>
   <feColorMatrix>
   <feComponentTransfer>
   <feComposite>
   <feConvolveMatrix>
   <feDiffuseLighting>
   <feDisplacementMap>
   <feFlood>
   <feGaussianBlur>
   <feImage>
   <feMerge>
   <feMorphology>
   <feOffset>
   <feSpecularLighting>
   <feTile>
   <feTurbulence>
   <feDistantLight>
   <fePointLight>
   <feSpotLight>

<path> uses the following commands:
M = moveto
L = lineto
H = horizontal lineto
V = vertical lineto
C = curveto
S = smooth curveto
Q = quadratic Bézier curve
T = smooth quadratic Bézier curveto
A = elliptical Arc
Z = closepath

All these commands can be written in small letters: m, l, h, v etc.
Small letters m, l, h, ... denote relative positions
Capital letters M, L, H, ... mean absolute positions