Terms table

• term_id
• name
• slug

Term_taxonomy table

• term_taxonomy_id
• term_id
• description

i want to show all record like "term_id , name , description"

my Term model

public function TermTaxonomy(){
    return $this->hasOne('TermTaxonomy');
}

my TermTaxonomy model

public function Term(){
    return $this->belongsTo('Term');
}

my route

$term = new Term;
$categories = $term->all(['term_id', 'name']);
foreach($categories as $category){
    echo $category->term_id . " " . $category->name . " " . "description of term_id should here" ; 
}

trying this code but Error Undefined property: Illuminate\Database\Eloquent\Collection::$TermTaxonomy

$e = new Term;
$f = $e->all(['term_id','name']);
    echo $f->TermTaxonomy->description;
}

with the above code i want to return all description of each term_id, but i am confusing why i can show description if the object just 1 , like this code below

$a = new Term;
$b = $a->all(['term_id','name'])->find(8);
echo $b->TermTaxonomy->description . "<br>"; // work return description of $b;

so what is exactly one to one relationship function ? is one to one only work when the object just 1 ?

what about in my case ? is my logic wrong to show all description using relationship method ? then what must i do to show term id , name , description lists ?

thanks in advance, i am totally newbie in laravel.