<p>Tensors (hypermatrices) are multidimensional analogs of matrices. In the last few years, the tensor splitting problem has attracted much attention and has been studied extensively, from theory to solution methods and applications. This work, with its two parts, aims to contribute to reviewing the state-of-the-art studies for the tensor splittings and iterative methods for solving multilinear systems (tensor equations). In the first part of this paper, some new comparison theorems for two regular and weak regular splittings of real tensors are derived. These theorems are extensions of the classical comparison theorems of splittings of matrices. We show that, under certain conditions, the iterates implied for solving the multilinear system <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\({\mathcal {A}}{\textbf{x}}^{m-1} ={\textbf{b}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="script">A</mi> <msup> <mrow> <mi mathvariant="bold">x</mi> </mrow> <mrow> <mi>m</mi> <mo>-</mo> <mn>1</mn> </mrow> </msup> <mo>=</mo> <mi mathvariant="bold">b</mi> </mrow> </math></EquationSource> </InlineEquation> are monotone. We generalize theorems about H-splittings from matrices to tensors. These and comparison theorems for two regular and weak regular splittings can be easily extended for complex tensors. In addition, we discuss triangular splitting, <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\({\mathcal {M}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="script">M</mi> </math></EquationSource> </InlineEquation>-splitting, <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\({\mathcal {H}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="script">H</mi> </math></EquationSource> </InlineEquation>-splitting, <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\({\mathcal {H}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="script">H</mi> </math></EquationSource> </InlineEquation>-compatible splitting, and direct splitting of tensors. Some iterative methods and associated comparison theorems for solving the multilinear system <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\({\mathcal {A}}{\textbf{x}}^{m-1} ={\textbf{b}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="script">A</mi> <msup> <mrow> <mi mathvariant="bold">x</mi> </mrow> <mrow> <mi>m</mi> <mo>-</mo> <mn>1</mn> </mrow> </msup> <mo>=</mo> <mi mathvariant="bold">b</mi> </mrow> </math></EquationSource> </InlineEquation>, when <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\({\mathcal {A}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="script">A</mi> </math></EquationSource> </InlineEquation> is an <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\({\mathcal {H}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="script">H</mi> </math></EquationSource> </InlineEquation>-tensor, and a fast and smooth iterative method to solve <InlineEquation ID="IEq8"> <EquationSource Format="TEX">\({\mathcal {A}}{\textbf{x}}^{m-1}={\textbf{b}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="script">A</mi> <msup> <mrow> <mi mathvariant="bold">x</mi> </mrow> <mrow> <mi>m</mi> <mo>-</mo> <mn>1</mn> </mrow> </msup> <mo>=</mo> <mi mathvariant="bold">b</mi> </mrow> </math></EquationSource> </InlineEquation> with the symmetric coefficient tensor <InlineEquation ID="IEq9"> <EquationSource Format="TEX">\({\mathcal {A}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="script">A</mi> </math></EquationSource> </InlineEquation> are given in the second part.</p>